Your device is not water-resistant. Keep it dry.

BACK-UP COPIES

Remember to make back-up copies or keep a written record of all important information.
CONNECTING TO OTHER DEVICES
When connecting to any other device, read its user guide for detailed safety instructions. Do not connect incompatible products.

About your device

When using the features in this device, obey all laws and respect privacy and legitimate rights of others. Warning: To use any features in this device, the device must be switched on. Do not switch the device on when wireless device use may cause interference or danger.

Network services

Contact your service provider for additional instructions for the use of network services and information on what charges will apply. Some networks may have limitations that affect how you can use network services. Your service provider may have requested that certain features be disabled or not activated in your device. Your device may also have been specially configured.

Shared memory

The following features in this device may share memory: bookmarks; image, audio, and video files; notes, sketch, and other files; contacts; e-mail messages; and applications. Use of one or more of these features may reduce the memory available for the remaining features sharing memory. For example, saving many images may use all of the available memory. Your device may display a message that the memory is full when you try to use a shared memory feature. In this case, delete some of the information or entries stored in the shared memory features before continuing.

Overview

1. Overview
The Nokia 770 Internet Tablet provides easy broadband access to the Internet through a WLAN/Wi-Fi or Bluetooth connection with compatible mobile phones. Its wide screen and portable size make it optimal for enjoying the Web and Internet communications away from your laptop or desktop. Your compatible WLAN access point must be compliant with the IEEE 802.11b or 802.11g standard. Read this user guide carefully before using your device. Read also the quick start guide provided with the device and the user guide of your compatible Nokia phone, which provides important safety and maintenance information.

Application title area

The application title area (2) displays the name of the active application and the name of the currently open file. To open the application menu, tap the title, or press the menu key.

Status indicator area

Tap the icons in the status indicator area to get more information or perform tasks related to a specific function. The status indicator area (3) may contain the following icons: indicates that you have set an alarm in the Clock application. indicates that the device is connected to a PC through a USB cable. The presence icon indicates your presence status and allows you to adjust the presence settings. The icon is visible only after you have created an account for Internet call and instant messaging service. indicates that you are online, that you are away, that you are invisible, or that you are offline. indicates the level of display brightness and allows you to adjust the display settings.
indicates the volume level and allows you to adjust the master volume and other sound settings. The more bars the icon contains, the higher the volume. When the sounds are muted, the icon is. The Internet connection icon indicates the status and type of the Internet connection and allows you to open and close an Internet connection. indicates that a WLAN connection is active, that a packet data connection (for example, GPRS) is active, that a data call connection (for example, GSM data call) is active, that there is no Internet connection, or that the device is in the offline mode where no connections are allowed. indicates how much charge is left in the battery. The more bars the icon contains, the more charge is left.
Minimize and close buttons
Every application has the minimize and close buttons (4). If you tap , the current application is hidden and the underlying application is shown. To bring the minimized application back to the top, tap its icon in the application switcher. If you tap , the current application view closes. To close an application, you can also select Close from the application menu or press the escape key for a second.

Hardware keys

A keypress refers to the press and release of a key. Some actions depend on the length of the keypress. Power key A short keypress opens the Device mode dialog. A long keypress turns the device on or off. Zoom key A short keypress changes the zoom level of the current view, and adjusts the volume in audio applications.
Full-screen key A short keypress switches between full screen and normal screen modes. Scroll key A short keypress moves the focus from one item to another in the respective direction. A long keypress in the Web browser scrolls the content of the active page or frame. Press the center of the scroll key to activate the highlighted item, and to accept confirmation notes. Escape key A short keypress removes the cursor from text fields, cancels menus and dialogs, and rejects confirmation notes. A long keypress closes the topmost dialog or application view. In the Web browser this key acts as a back button. Menu key A short keypress opens and closes the application menu. Home key A short keypress opens the home view of the device. A long keypress activates the application switcher.

Text input methods

You can enter letters, numbers, and special characters in two ways. The keyboards allow you to tap characters with the stylus or your fingers. Handwriting recognition allows you to write characters directly onto the screen using the stylus as a pen. To begin text input, tap any text field with the stylus or your fingers. The text input area appears on the touch screen and displays one of the keyboards or the handwriting recognition area, depending on the previously used text input method. To switch between text input methods, tap on the keyboards or handwriting recognition view, and select Input method and the desired option. Start writing. Your device can complete words based on the built-in dictionary for the selected text input language. The device also learns new words from your input.

On-screen keyboard

Tabulator key (1) Adds a tabulator space or moves the cursor to the next available text input field. [ABC] (2) Locks the uppercase characters of the keyboard. In the handwriting recognition mode, switches between the normal and special character recognition modes. Shift key (3) Enters an uppercase character in the on-screen keyboard mode when you write in lowercase. When you tap this key in the handwriting recognition mode, the last lowercase character switches to uppercase, and vice versa. Input menu key (4) Opens the text input menu, which includes commands such as Edit > Copy, Cut, and Paste. On-screen keyboard (5) Space bar (6) Inserts a space. Numeric keyboard (7) Backspace key (8) Deletes the character to the left of the cursor. Enter key (9) Moves the cursor to the next row or text input field. Additional functions are based on the current context (for example, in the Web address field of the Web browser, it acts as a go button). Special character key (10) Opens a view, in which you can select from commonly used special characters, symbols, and language character accents. Close (11) Closes the on-screen keyboard and handwriting recognition input area, and saves changes.

Full-screen finger keyboard
To begin text input with the finger keyboard, tap the text input field with your fingers. The finger keyboard opens in the full screen mode. The finger keyboard displays buttons and functions similar to the other text input methods; however, not all of the special characters are available. To close the finger keyboard, tap keyboard. in the upper right corner of the , and select Tools >
To change the finger keyboard settings, tap Control panel > Text input settings > Finger.
When using the finger keyboard, use only clean hands and regularly clean the touch screen by wiping the screen gently with a dry, soft cloth.

Handwriting recognition

You can use the stylus as a pen to write text. Write legible, upright characters on the text input area, and leave a small horizontal gap between each character. Do not use cursive writing.
To write common characters and numbers (default mode), write words as you normally write them. To write special characters, tap [Abc1] in the left pane of the input area, and write the characters as you normally write them. To insert new characters in and after words, draw them in the intended positions. To teach the device your handwriting style, tap keyboard, and select Tools > Teach. To use handwriting gestures, see the figure. Draw gesture 1 for a backspace or gesture 2 for a space. on the on-screen

Text input settings

To define the text input settings, tap Control panel > Text input settings. , and select Tools > Word completion: is turned on by default. To turn word completion off, clear the selection. When word completion is on, the device displays word candidates that match the first characters of the word that you enter with the on-screen keyboard or write by hand.

Volume control

To adjust the master volume, tap to access the sound settings. To decrease or increase the volume, drag the volume slider to the desired position. The master volume overrides all other volume settings in the device. Warning: Listen to music at a moderate level. Continuous exposure to high volume may damage your hearing. Do not hold the device near your ear when the loudspeaker is in use, because the volume may be extremely loud.

Device lock

To prevent unauthorized use of your device, change the lock code, and set the device to automatically lock after a certain time-out period. To lock the device, briefly press the power key, select Lock device, and tap OK. If you have not set the lock code, you are asked to do so. To unlock the device, enter the lock code, and tap OK. To edit the device lock settings, tap Control panel > Device lock. , and select Tools >

To set the time-out period, tap Lock device after, and select the desired time.

Change the lock code

To change the lock code, do the following: 1. Tap , and select Tools > Control panel > Device lock > Change lock code.
2. Enter the current lock code (the default code is 12345), and tap OK. 3. Enter the new code, and tap OK. 4. Enter the new code again, and tap OK. If you tap Cancel in any of these dialogs, the device lock code is not changed. Keep the new code secret and in a safe place separate from your device. Note: If you lose the device lock code, you must take the device to a Nokia authorized service facility. To unlock the device, the software must be reloaded, and all data you have saved in the device may be lost.
Lock touch screen and keys
To lock the touch screen and keys, briefly press the power key, and select Lock touch screen and keys > OK. To unlock the touch screen and keys, press the power key and the center of the scroll key.

Memory management

To view current memory consumption, tap Control panel > Memory. , and select Tools > To view the amount of free and used memory, and the memory consumption of different items on your device or memory card, select the Device or Memory card page. To use the memory card as additional virtual memory for running applications, open the Virtual page, and select Extend virtual memory. Additional virtual memory is always tied to the memory card that you are currently using. Important: Do not remove the MMC card in the middle of an operation when the card is being accessed. Removing the card in the middle of an operation may damage the memory card as well as the device, and data stored on the card may be corrupted.
To free memory, delete data in File manager or other applications. To find and delete files of a certain size, use the Search application. The applications display error messages when you try to move, copy, or save files, and when there is not enough memory on the device or the memory card.

Memory card

You can only use FAT 16/32 formatted memory cards with this device. To view and manage the contents of the memory card, tap , select File manager, and tap the memory card icon in the folder list. To rename a memory card, select File manager > Memory card > Rename. To format a memory card, select File manager > Memory card > Format. All data is permanently deleted from the memory card. Tap Format.

Back up and restore data

You can back up data to a memory card and restore it, if necessary. The backup appears as a folder on the memory card. You can also secure the backups with a password. To back up data, do the following: 1. Tap , and select Tools > Control panel > Backup/Restore > Backup. 2. In the Backup selection dialog, change the name of the backup; tap the name, and enter a new one. 3. In the Data selection dialog, select whether you want to back up all data or only the specified data types. You cannot make back-up copies of applications you have installed. To protect the backup with a password, tap Protect with password, enter twice the password you want to use, and tap OK.

Communicate over the Web

To view the Web page in optimized size, select Web > View > Optimised view. The Web page is fit to the width of the screen; text and images are zoomed and scaled differently, if necessary. To change the Web browser settings, select Web > Tools > Settings. For more information, see the help of the application.

Manage bookmarks

To manage the bookmarks you saved in the device, tap , and select Bookmarks. The bookmark folders are shown on the left, and the bookmarks in the selected folder on the right. Note: Your device may have some bookmarks loaded for sites not affiliated with Nokia. Nokia does not warrant or endorse these sites. If you choose to access them, you should take the same precautions, for security and content, as you would with any Internet site. You may not be able to edit or manage the contents of the Internet service providers bookmarks. To open a folder and a bookmark contained in it, tap the folder, and tap the bookmark twice. To add a bookmark to the current Web page, hold the stylus down on the Web page, and select Add bookmark. from the context-sensitive menu. To save a link as a bookmark, hold the stylus down on the link for a second, and select Add link to Bookmarks.
4. Communicate over the Web
To be able to communicate over the Web, you must have an active network connection and registered user accounts and passwords for Internet call, instant messaging and e-mail services with service providers outside Nokia.
You can have multiple accounts for Internet call and instant messaging services. By default, your device supports the Jabber and Google Talk services. Note: It is recommended to use WLAN connection for Internet calls, because cellular connection is dependent on networks.

Accounts

To access the account setup wizard, tap Control panel > Accounts > New. , and select Tools > To complete and save the account settings, do the following: 1. Account setup: Welcome Tap Next to begin the account setup. 2. Account setup: Service Select the desired service from the list, and tap Next. 3. Account setup: Select When you select the Jabber or Google Talk service, you are asked to confirm whether you want to start using an existing Jabber or Google Talk account with this device, or create a new account. If you select to create a new Jabber or Google Talk account, you need an active Internet connection, because you register the new account online. 4. Account setup - User name, define the following settings: User name Enter the user name for the account. If you are defining a Google Talk user name, enter the full Gmail user name (everything before @gmail.com). Password Enter a password for the account. Verify password Enter the password again. This option is only available if you selected to create a new Jabber account. To define the advanced settings for the selected account, tap Advanced. This option is not available for all accounts. For more information on the accounts, see the help of the application. To save the account settings, tap Finish.

To edit the settings of an account, set your presence status to Off, select the account, and tap Edit. To delete an account, select the account, and tap Delete.

Presence

Presence is a network service that allows you to share your presence status with those who have access to the service and request it. When you create and register an account for Internet call and instant messaging service, your presence status is connected to that account. Your presence status can be On, Away, Invisible, or Off. To change your presence status, tap To define your presence settings, tap Control panel > Presence. on the status indicator area. , and select Tools >

Contacts

Use Contacts to manage contact information and start communications with your contacts. Tap , and select View contacts. The main view of Contacts displays the contact information in two panes. The group pane on the left lists available groups, and the content pane on the right shows the contacts of a selected group and the presence status of the contacts. To add a contact, select Contacts > Contact > New contact. To group contacts, drag them into the desired groups. You can assign a contact to many groups, and a group can contain many contacts. To create a new group of contacts, select Contacts > Group > New group. To search for a contact, tap in the lower right corner of the screen. Enter the search words, and tap. To start communicating with a contact, select a contact from the list, and tap it with the stylus. In the Contact dialog, tap an available channel for communication: to give a call to the contact
to chat with the contact send an e-mail message to the contact Tip: To be able to make contact, you must define account settings for the Internet call and instant messaging services. For more information, see "Accounts," p. 28.

Instant messaging

Instant messaging application allows you to instantly communicate with people over the Internet. To be able to use this feature, you must have and active network connection, a registered instant messaging account with a service provider, and a presence status that allows sending and receiving messages. By default, your device supports the Jabber and Google Talk services. To access the Instant messaging application, tap New chat. , and select

To create an account for instant messaging services, tap the application menu title, and select Tools > Accounts. Follow the instructions on the screen to complete and save the account settings. To enter a chat room, tap the application menu title, and select Chat > Enter chat room. In the Enter chat room dialog, enter the name of the chat room in the Room name field, or select the room from the list. To join the chat room, tap OK. If the chat room is protected by a password, the Enter password dialog is displayed. To join the protected chat, enter the correct password, and tap OK. To write and send a chat message, tap the text field in the chat toolbar, enter the message, and tap. To add smileys to your messages, tap. To view other messages, scroll the list with the stylus. The most recent message is always displayed at the bottom of the list. To end the chat, tap in the upper right corner of the screen.

Internet call

Internet call is based on the voice over Internet protocol (VoIP) that allows you to make and receive calls over the Internet. To be able to use this feature, you must have an active network connection, a registered Internet call account with a service provider, and a presence status that allows receiving calls (On or Away). Important: Emergency calls are not supported. To access the Internet call application, tap , and select New call.
To create an account for Internet call service, select Internet call > Tools > Edit accounts. Follow the instructions on the screen to complete and save the account settings. To make a Internet call, select Internet call > Internet call > New. After you select a contact and start the call, a call request is sent to the call recipient. If the recipient accepts the call request, the call is activated. You can only have one Internet call at a time. No group or conference calls are possible. The Incoming call dialog is displayed when you receive a notification of an incoming Internet call. To answer the call, tap. To reject the call, tap. To silence the call, tap. To block the call, tap , and select Block caller. All incoming call requests from that caller are rejected, and you receive no indication of them. To adjust the volume of an Internet call, drag the volume slider with the stylus. To mute a call, tap below the volume slider. When the call is muted, you can listen to what the other person is saying, but that person cannot hear your voice. To unmute the call, tap the icon again. Warning: Do not hold the device near your ear when the loudspeaker is in use, because the volume may be extremely loud. To end an Internet net call, tap. When you end a call, a call summary is displayed, and you are given some options.

E-mail sent to you is not automatically received by your device, but by your remote mailbox on the e-mail server. To read your e-mail, you must first connect to the mailbox and retrieve the e-mail messages to your device. To retrieve e-mail from a remote mailbox, select E-mail > E-mail > Send & receive. Select to retrieve e-mail from all mailboxes or from a selected mailbox. If you have e-mail in the Outbox folder, these messages are sent simultaneously. To open a message, tap twice the header of the message you want to read.
Important: Exercise caution when opening messages. E-mail messages may contain malicious software or otherwise be harmful to your device.

Create and send e-mail

To create a new e-mail message, do the following: 1. Tap , and select New e-mail. 2. Write the recipients e-mail address. Add a semicolon (;) to separate multiple recipients. If the recipients are in Contacts, tap , and select the recipients from the list. 3. Fill in the subject, and write the message. To send the message, tap.

Inbox folder

The Inbox folder contains received messages. The headers of unread messages are shown in bold. To send a new message, tap. To reply to a message, tap. To send a reply to the sender of a message and to the recipients in the CC field, tap. To forward a message, tap. To delete a message, tap. To send all unsent messages and receive all new messages, tap. To search for a message, select E-mail > Tools > Search e-mails.

Outbox folder

Messages waiting to be sent are saved temporarily in the Outbox folder. The status of each message is shown next to the message header: On request The message is sent only if you tap the message and Suspended The sending of the message was canceled using the Cancel sending function. Failed The message could not be sent. Waiting The message will be sent the next time you connect to your mailbox.
Media players and viewers
To send the selected message again, tap the selected message, tap.
.To cancel the sending of

Sent folder

After a message is sent, it is moved to the Sent folder. To specify the settings of the Sent folder, select E-mail > Folders > Folder settings. Define the following: Sent folder clean-up on: Select this option to allow automatic deletion of sent messages. Remove messages older than: Select how often the sent messages are deleted. Select time: Select how the interval for deletion is measured: in days, weeks, or months.

Drafts folder

In the Drafts folder, you can save unfinished messages or messages that you want to send later.
5. Media players and viewers
When you listen to audio files and streams, or view videos, the master volume settings override all other volume settings in the device.

Audio player

You can listen to music and other audio files stored on your device or memory card, and listen to audio streams from the Internet. You can also create and manage playlists. Tap , and select Audio player. The audio player supports the following file formats: AAC, AMR, AWB, M3U, MP2, MP3, PLS, WAV, and WMA. The player does not necessarily support all the variations of a file format.

The supported audio stream formats are: AAC, AMR, AMRWB, MP2, MP3, and WAV. Streaming performance depends on the bandwidth availability.

Internet radio

With Internet radio you can listen to Internet radio channels or any other compatible audio streams. The Internet radio supports MP3 file format, and M3U, PLS, RAM, and RPM playlists. To add a radio channel to the playlist, do the following: 1. In the Web browser, search for the desired radio channel stream, and use the context-sensitive menu to copy the address of that stream. Hold the stylus down on the link for a second, and select Copy link location. 2. In the home view of the device, tap The Audio player application opens. in the Internet radio dialog.
3. Select Audio player > Playlist > Add stream. 4. Tap the Web address field, and paste the link of the radio channel stream. Tap OK. 5. Select Audio player > Playlist > Save. To listen to a radio channel, select the desired channel from the playlist in the Internet radio dialog, and tap. To stop listening, tap. To adjust the volume, tap , and drag the slider with the stylus. To close the volume control dialog, tap anywhere outside it.

Video player

To watch video clips stored on your device or memory card, or watch streaming videos from the Internet, tap , and select Video player. The video player supports the following file formats: MPE, MPEG, MPG, RA, RAM, RM, RMJ, RMVB, RPM, RV, AVI (containing MPEG4 or H.263 video and MP3 audio), and 3GP/3GPP (containing MPEG4 or H.263 video and AMR or AAC audio). The video player does not necessarily support all the variations of a file format. 36
The supported video stream formats are: MPE, MPEG, MPG, RA, RM, RMJ, RMVB, RV, AVI, and 3GP/3GPP. Streaming performance depends on the bandwidth availability.

RSS feed reader

You can receive and read RSS news feeds from service providers. The service provider may be a news agency, entertainment site, or an individual who writes an online diary or journal. Tap , and select RSS feed reader. The news folders and feeds you have created are shown on the left. There may also be predefined folders and feeds. To subscribe to a news feed, do the following: 1. In the Web browser, search for a link labeled XML or RSS, and use the context-sensitive menu to copy the address of that link. Hold the stylus down on the link for a second, and select Copy link location. 2. In RSS feed reader, tap on the application toolbar, and paste the address of the news feed to the Add feed dialog. The RSS feed reader supports the following file formats: Rich Site Summary, RDF Site Summary, Really Simple Syndication (all are also known as RSS), and Atom.

Additional safety information
Do not drop, knock, or shake the device. Rough handling can break internal circuit boards and fine mechanics. Do not use harsh chemicals, cleaning solvents, or strong detergents to clean the device. Do not paint the device. Paint can clog the moving parts and prevent proper operation. Use chargers indoors. Always create a backup of data you want to keep (such as contacts and e-mail messages) before sending your device to a service facility. All of the above suggestions apply equally to your device, battery, charger, or any enhancement. If any device is not working properly, take it to the nearest authorized service facility for service.
Your device and its enhancements may contain small parts. Keep them out of the reach of small children.

Operating environment

Remember to follow any special regulations in force in any area, and always switch off your device when its use is prohibited or when it may cause interference or danger. Use the device only in its normal operating positions. This device meets RF exposure guidelines when used either in the normal use position or when positioned at least 1.0 centimeters (3/8 inches) away from the body. When a carry case, belt clip, or holder is used for body-worn operation, it should not contain metal and should position the device the above-stated distance from your body. To transmit data files or messages, this device requires a quality connection to the network. In some cases, transmission of data files or messages may be delayed until such a connection is available. Ensure the above separation distance instructions are followed until the transmission is completed. Parts of the device are magnetic. Metallic materials may be attracted to the device, and persons with a hearing aid should not hold the device to the ear with the hearing aid. Do not place credit cards or other magnetic storage media near the device, because information stored on them may be erased.
The product is compliant with the following standards: EN 300328-2, Harmonised standard for Data Transmission Equipment Operating in the 2.4 GHz Band. EN 50360, Product Standard to demonstrate the Compliance of Mobile Phones with the Basic Restrictions related to Human Exposure to Electromagnetic Fields. EN 301 489-01, Electro Magnetic Compatibility Standard for Radio Equipment and Services. EN 301 489-17, Specific (EMC) Conditions for Wideband Data and Hiperlan Equipment. EN 60950/IEC950, Safety of Information Technology Equipment. 1999/5/EC, Council Recommendation on the Limitation of Exposure of the General Public to Electromagnetic Fields. Please check compliance with other standards separately.

Open source software notice
This product includes certain software originating from third parties that is subject to 1. the GNU Library/Lesser General Public License (LGPL), 2. the GNU General Public License (GPL), and 3. different and/or additional copyright licenses, disclaimers, acknowledgements, and notices. The LGPL, GPL and said certain other licenses are available at www.nokia.com/support/770. You may obtain a complete corresponding machine-readable copy of the source code of such software under the LGPL and the GPL at www.nokia.com/support/770. Alternatively, Nokia offers to provide such source code to you on CD-ROM for a charge covering the cost of performing such distribution, such as the cost of media, shipping, and handling, upon written request to Nokia at: Source Code Requests Multimedia Nokia Corporation P.O.Box 407 FIN-00045 Nokia Group FINLAND
This offer is valid for a period of three (3) years from the date of the distribution of this product by Nokia. Please refer to the exact terms of the LGPL and the GPL regarding your rights under said licenses.
This software is based in part on the work of the Independent JPEG Group. The Graphics Interchange Format is the Copyright property of CompuServe Incorporated. GIF SM is a Service Mark property of CompuServe Incorporated. This product includes software developed by: Computing Services at Carnegie Mellon University (http://www.cmu.edu/computing/) Tommi Komulainen <Tommi.Komulainen@iki.fi>
The Australian National University
The OpenSSL Project for use in the OpenSSL Toolkit (http://www.openssl.org/) Gregory M. Christy Pedro Roque Marques Eric Rosenquist, Strata Software Limited The XFree86 Project, Inc (http://www.xfree86.org/) and its contributors The FreeType Team

2.1.1 Symmetric encryption
The basic concept of symmetric encryption is that the symmetric algorithm uses the same key for encryption and decryption. An application for symmetric encryption is the encryption of communication data with a key, K, between two entities, for example Alice and Bob. Alice and Bob have already acquired somehow the same key, K. When Alice encrypts the plaintext into the resulting ciphertext with the key K, Bob can decrypt the ciphertext with the same key K. This principle can also be used for securely sending data over an insecure communication channel. Other persons not having the key K, are not able to decrypt the ciphertext retrieved from the communication channel into the original plaintext. Below we give some properties of symmetric encryption in formulas: E(KA, M) = M', encrypts the plaintext M, into the resulting ciphertext, M'. D(KB, P) = P', decrypts the ciphertext, P into P'. D(KA,E(KB, plaintext))=plaintext if KA= KB E(KA, M) is the encryption function with the following parameters: the key, KA and the plaintext, M. The result of function E will be the ciphertext, M'.

Page 8/45

Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics D(KB, P) is the decryption function with the following parameters: the key, KA and the ciphertext, P. The result of function D will be P'. The decryption function will only return the original plaintext if the keys are the same (KA=KB). There are a number of different symmetric encryption algorithms: two popular and well-known encryption algorithms are Advanced Encryption Standard (AES) and Blowfish. AES supports 128/192/256 bits key sizes. Blowfish has variable key length with the maximum length of 448 bits.
2.1.2 Asymmetric encryption
An asymmetric encryption is an algorithm, which uses one key for encryption and an other key for decryption and vice versa. Each party generates one pair of keys: one key, the private key, is only known by the owner. The second key, the public key, is public and everybody is allowed to know this key. The pair of keys are generated in such a manner that, if the plaintext is encrypted with the private key, it can only be decrypted with the public key and vice versa. Some examples of an asymmetric encryption algorithm are ElGamal and RSA (Rivest, Shamir and Addleman). ElGamal and RSA are based on the discrete logarithms problem and these keys must have a relative large key length to be secure enough. A 1024 bits key is usually recommended as minimum key length. More information can be found in [MI-TSS]. Another kind of asymmetric cryptographic algorithm is one based on elliptic curves. The advantage of elliptic curves algorithm is for the keys to be much smaller. Additionally this algorithm is less computationally expensive than cryptographic algorithms based on discrete logarithm problems. It is claimed that a 160-bit public key based on elliptic curves scheme is as secure as a 1024-bit public key based on the RSA scheme.

Page 10/45

Figure 1: Message sequence of the Diffie-Hellman key exchange. 8. B now knows the A's public key. Therefore B can calculate the new symmetric key between A and B. Calculation of the new key can be done as follows: b PB=g mod p b a b a b (PA) mod p = ( g mod p ) mod p = (g ) mod p = KBA 9. B sends to A its public key. B -> A: PB 10. A now knows the B's public key. Therefore A can calculate the new symmetric key between B and A. Calculation of the new key can be done as follows: b PB=g mod p b b a b a (PA) mod p = ( g mod p ) mod p = (g ) mod p = KAB To prove, that the keys generated on A and B are the same: (gb ) a mod p = gba mod p =(ga)b mod p = KAB = KBA An advantage of Diffie-Hellman is that it can establish a shared key over an insecure channel. Both parties have established the same pairwise key (KAB = KBA) with the other's public key and its own private key. The protocol is confidential in the sense that the private key can not be known by others. A known weakness in the Diffie-Hellman Key exchange is that authentication is not provided. A and B do not have any guarantee that they are communicating together. An intruder may pretend that he is B and can lure A into key exchange. This kind of attack is known as middle person attack, or man in the middle attack. The PFP which will be discussed later, is designed to solve the vulnerability of middleperson attack by using a out of band channel for authentication.

Page 11/45

One-way functions
One-way functions are functions where it is easy to compute the result of such function, but computationally infeasible to calculate the parameters if only the result is known. One-way functions are often used in security protocols as well as in other applications. A hash function is an one-way function and its properties are discussed in this report, because it is used in the PFP. An other kind of one-way function is a MAC function and can be used for the authenticity and integrity of a message.

2.3.1 Hash functions

A hash function is a function that accepts data of arbitrary length, called the pre-image and generates a fixed-size output, called the hash value [MI-TSS]. Reconstruction of the piece of data from the hash value should be computationally unfeasible. The hash value will not reveal any usable information about the piece of data that being hashed. The one-way hash function H(M) computes a fixed-length hash value, h from message, M of arbitrary length, as follows: h=H(M) A one-way hash function has the following properties: for a any value of M, it is relatively easy to compute the hash value, h for any value of h, it computationally unfeasible to compute M. for a message M it is very difficult to find an other message M' that has the same hash value such h(M)=h(M') Some examples of well-known popular hash-function are MD5, SHA-1 and SHA-256 with a length of 128, 160 and 256 bits, respectively. SHA-1 and SHA-256 will be used in this report.

2.3.2 Message Authentication Codes (MACs)
A message authentication code (MAC) is a short piece of information used for authenticating a message. A MAC algorithm accepts as input an arbitrary-length message and a secret key and outputs a mac value. A MAC function is comparable to a hash-function, but can protect the integrity of a piece of data and its authenticity as well. The mac function MAC(K,M) computes the mac value from a message M of arbitrary length and with as key K, as follows: MAC (K, M )=mac A MAC function has the following properties: for a any value of M and K, it is relatively easy to compute the mac value.

Page 12/45

for any given K, it computationally unfeasible to compute a new pair (M',K) such that MAC (K ,M ) = mac = MAC (K ,M')
For example, when two parties have pre-established a key, K and want to be certain that message is coming from each other, they calculate the encrypted mac value and append this to a message. The receiving party can also calculate the mac and if the received mac is the same as the calculate mac, they are certain that it is coming from each other. Example of a MAC function is HMAC and DAA. The HMAC function used in the PFP application is a 160-bits MAC function and uses SHA-1 for calculation the mac value.

Page 13/45

PFP key exchange protocol
The PFP is a protocol to establish a pairwise key or when they have already pre-established a key, this protocol should able to validate if this key is still the same on both sides. A pairwise key is a key that is only known to one pair of devices. For each secure association between two devices, a different key is used and therefore a new key has to be established by each pair. The PFP is based on the Diffie-Hellmann key exchange to securely establish key parameters. Afterwards, both devices use these parameters to generate the new pairwise key, which we shall call the Permanent Key. This Chapter describes and analyzes the PFP and its implementation.

3.4.1 PFP Key Exchange

The message sequence of the key-exchange scenario is displayed in the next diagram (Figure 2). The second section in Figure 2 is the part of message sequence where the actual key exchange is performed. The message sequence scenario, which is described in the following sections, assumes that device A and device B have not yet exchanged a permanent key and want to establish a new one. 1. The client, A, connects to server, B, and B sends its Magnet_ID to A with the message Req_ID() B -> A: Req_ID( SHA-1( gbmod p ) )

Page 16/45

Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics 2. A receives the message Req_ID and searches the Magnet_ID in the local database whether A can find the identity of B or not. Subsequently the following two situations can occur: A finds the B's identity and returns the corresponding PKID and Magnet_ID to B. This key validation scenario is discussed in Section 3.4.2 later on. A does not find B's identity and returns an EAP_FAILURE message to B. This key scenario will be explained here. As A cannot find B's identity and corresponding key, A must enter into key exchange mode to establish a new key with B. Subsequently A sends a new generated code, K, to the PAC. In the case when the PAC is the user, it would display K to the user and it is followed by entering K into device B. A -> B: EAP_FAILURE() A -> PAC: K 3. B receives the EAP_FAILURE() message, which triggers B to enter also into key exchange mode. B then receives K from the PAC. In our case K will be displayed on A and the user must enter the code into device B. 4. B starts the key exchange by sending an empty Req_ID() message to A. B -> A: Req_ID() 5. A receives this request message and returns the Resp_PFPBegin message containing its public key, PA = ga mod p. A -> B: Resp_PFPBEGIN(ga mod p) 6. B receives the message Resp_PFPBegin and retrieves A's public key. B calculates the new temporary key, TKAB = (ga)b mod p, according to Diffie-Hellman. B then returns the Req_PFPExchange message. which contains the following: b The public key of B, PB = g mod p. HMAC of the B's public key encrypted with the key (code), K. The TKAB encrypted ciphertext contains B's nonce and the HMAC of B's public key. B -> A: Req_PFP_Exchange (gb mod p | HMAC(K,gb mod p) | E(gab mod p, NB | HMAC(K,gb mod p) ) The reason for sending unencrypted a second HMAC in the message is that A can easily authenticate B's public key without decrypting the message. More information about how the HMACs are used for authentication will be discussed later in Section 3.4.3.

A solution for this problem is compiling the source code on an other system, the host system, which can also compile source files for another computer architecture. This kind of compilation is called

Page 23/45

Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics cross-compiling. After the compilation the executables can be copied to the device and the Nokia 770 can execute the program. For the Nokia 770 there are two tools available, which aid in compiling the executables for the Nokia 770:
Scratchbox, which is a cross-compilation toolkit for the ARM processor. This toolkit enables you to compile and to emulate programs for the Nokia 770, which has an ARM processor, on the host system. Maemo, which is a development platform for creating applications for the Nokia 770. A Maemo package can be added to the Scratchbox, such that the host-system has the same environment as on the Nokia 770.
Of course the implementation should also be capable to run on devices that do not have the Hildon library. Then it could be compiled without the Hildon library and uses the GTK+ library as replacement.
3.5.4 Executing PFP on the Nokia 770
In the MAGNET documentation [MD4.3.3], a detailed description on can be found on how to start the PFP application on a normal computer. How to run the PFP application on the Nokia 770 is more complex and therefore it will be briefly discussed below:
Install Scratchbox and Maemo on the host system. Install the sqlite3 package for the Nokia 770 on the host-system, or compile and install the SQLITE 3 library in your scratchbox environment on your host-system. Compile the PFP application for the ARM processor in the Scratchbox environment. On the Nokia: Download and install the following packages from the Maemo website:
sqlite3 xterm dropbear maemopad
Copy the PFP application with executables to the Nokia 770 flashcard. On the Nokia 770:
Start xterm Login as root with default password 'rootme':
$ dbclient root@localhost

Page 24/45

Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics Edit /etc/bluetooth/hcid.conf with Maemopad or with an other editor to disable security and to enable scanning (See Section 3.5.2) Copy the PFP application into a directory:

An implementation problem of using the whole key for encryption, is that many well-known symmetric encryptions do not support such large key length, therefore a conversion to a much smaller symmetric key should be made. For example, a hash such as SHA-256 or SHA-1, could be used for this type of conversion and the author of the PFP application is making these changes into the PFP implementation.
3.5.6 Known problems in the implementation
The are some problems executing the PFP protocol:
The PFP implementation uses the OPENSSL library, which supports the SHA-256 hash function. Older libraries than version 0.9.8a have not implemented the SHA-256 function. In order to get older versions working, the SHA-1 function must be used to generate the permanent key. To use the SHA-1 function instead of the SHA-256 the following line must be uncommented in the file pfp.h

#define NOSHA256 1

Moreover, all other devices have to use the SHA-1 function instead of the SHA-256 for compatibility reasons. The Nokia 770 only has version 0.9.7 of the OPENSSL library, therefore to get it working with other devices, the SHA-1 function must be used on all the devices.
Some new compilers compile source files with stack protection. As the PFP implementation is still in development and in debugging phase, the application detects in some situations at run time a buffer overflow. Of course these buffer overflow bugs have to be fixed. To compile without stack protection the following flag has to be added to the compiler options:

-fno-stack-protector

A dialog might not be shown for entering or for displaying the code to the user. Instead the standard console input and output will then be used. One of the following situations causes this problem: Page 26/45
The PFP application starts another program for showing the dialogs and cannot find this executable. To solve this problem, check if the executables server-pfp/server-pfp and clientfp/client-pfp are in the right directory and check if the executables in the functions server_pac and client_pac of the file eap_pfp.c refers to the right directory. function server_pac:

strcpy(command, "<path to server-pfp>/server-pfp "); strcpy(command, "<path to client-pfp>/client-pfp ");

function client_pac:

To display the dialogs, a xserver must be running and we must set the DISPLAY variable to the xserver. For the PFP it makes no sense to run it elsewhere, so the DISPLAY variable will be set to the first xserver on the localhost:

export DISPLAY=:0

Page 27/45
The implementation of a GUI for the PFP
The PFP application can only be started from the command line, which is not very user friendly, so a simple graphical user-interface is needed. The Nokia 770 also has a limited user-interface: it only has a few buttons and a touchscreen, so starting the PFP from the command line interface (CLI) is not very practical, especially when a lot of command line options have to be provided. A new Graphical User Interface (GUI) therefore simplifies the process of discovering devices in the neighborhood and the start of the PFP application for exchanging keys between devices. This chapter describes the development of this GUI.

Requirements

Because the user interface for the PFP is not that complex, there is only a short list of requirements for the user-interface.
The user interface should be very simple, so that within a few clicks we can complete the process of imprinting. The user interface should be executable on the Nokia 770 and also on personal computers with Linux. The user interface should be able to scan for Bluetooth devices in the neighborhood. The user interface should be able to start the PFP server. The user interface should be able to start the PFP client connecting to a PFP server application. The user interface should be able to reset the imprinting database.

Operating Environment

This section will describe the operating environment needed to start and compile the PFP application. As the PFP implementation is written for Linux, the new GUI should also be written for Linux. The implementation of the user-interface must also be compatible with the Nokia 770 environment, which has a different computer architecture than most computers. The new GUI implementation makes use of the GTK+ library, which is a library for creating userinterfaces and which is supported on most Linux Distributions and also on the Nokia 770. Additionally, a special graphical user interface library for the Nokia 770, the Hildon library, is supported by this new implementation. This Hildon library [HILDON] adds the look and feel of the Nokia 770 desktop environment to the applications that uses the GTK+ library for the user-interface. Applications written for the GTK+ library can easily be adapted to support Hildon. The Hildon library is only supported on the Nokia 770 devices, but there is a development environment available, which can emulate the Nokia 770 device and supports this Hildon library.

If an event occurs, it will execute the corresponding assigned callback function. Execution of this callback function must be handled quickly and should not block for too long, otherwise the thread can not react to other events. In the GUI implemenation, the blocking thread problem is solved by creating a new thread handling this event. The older thread will end the callback function and can react to other events.
4.7 Analyzing the GUI Implementation
The GUI implementation performs its task well, however it is only able to scan bluetooth devices. As only the link-layer has the functionality to discover link connections, scanning devices using IP-layer is difficult and has to be researched. The UCL layer designed in MAGNET may solve this problem, but how this can be fit into PFP and the PFP-GUI still has to be researched [MD4.3.3] (see also problem described in Section 3.5.5) Page 31/45
Transitive PFP Imprinting
This Chapter describes an extension for the PFP for minimizing the number of user-interactions which is necessary to establish keys among pairs of devices. This extension is called Transitive PFP imprinting (TPFP). We give a description and specification of the TPFP in this Chapter. The PFP requires the user to authenticate with the PAC each time, when a pair of devices in a network wishes to exchange keys. In our case the PAC will be the user and each imprinting procedure the user has to enter a code into one of the devices. When a network consists of N devices, a total of N N 1/2 pairwise keys have to be established and the user is bothered each time. For example if we only have 8 devices in our network, the user must interact 8*7/2=28 times with his devices to establish a full secure network.
Figure 7: Transitive imprinting, where two devices, A and B are able to establish a secure association with each other via an intermediate device, T. A solution for this user-authentication problem is to exchange keys via intermediate device with which both devices have already established a secure association. The intermediate device has not the role of a central device, but acts transitively and forwards the key exchange between the two parties wanting to imprint. This kind of imprinting has been introduced in MAGNET as transitive imprinting. Any specification about transitive imprinting procedure has not been realized and therefore this Chapter specifies a transitive imprinting protocol based on the existing PFP. Figure 7 illustrates the general concept of transitive imprinting. We give a more description about this transitive imprinting procedure below: Assuming that devices A and B wishes to establish a pairwise key and already having a secure association with common device T. T acts as an intermediate device for establishing keys between A

Page 32/45

Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics and B 1. T establishes a secure connection with A and B, therefore A and B have a mutual secure indirect connection and can exchange key parameters indirectly via T. After the exchange of the nonces and the public keys, a new key can be generated in the same manner as in the PFP application (Section 3.3). User-interaction for authentication is not needed anymore, because the end-devices A and B are able to authenticate with T. The devices are able to detect if a received encrypted message is not coming from T or if it is modified.

Transitive Imprinting in the PN
Transitive imprinting could theoretically be used in any type of network. This Section describes how the transitive imprinting fits into the initialization of a personal network (PN). In the rest of the Chapter we will use the word node if we mean a device, which is part of a secure network or wants to be part of this secure network. The first secure association of a node in the PN must always be established by manual imprinting, because the node have not a trust relationship with any node yet and therefore authentication can only be provided by the user. After the manual imprinting, the node transitive imprints with all the possible nodes and in the end it registers itself into the PN.
Figure 8: Overview of imprinting a new node A with nodes in the PN.
1 Of course A and C, or B and C can also establish a key with intermediate device T

Page 33/45

Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics Figure 8 gives an overview of the PN initialization: Assuming that node B has already registered itself into the personal network and therefore has already secure associations with other nodes in the PN. The user wishes to manual imprint node A with node B and subsequently A can registered itself via B into the PN: 1. Discovery of devices: A discovers nodes that are in range and these nodes are potential partners for manual imprinting. In our case, A discovers that B is suitable for imprinting and displays B's address to the user. This first discovery procedure is accomplished by using the PFP GUI described in Chapter 4. 2. Manual PFP imprinting: The user starts the manual imprinting procedure on the both nodes: he starts the PFP server on B and he connects the PFP client, A, to B. After this PFP imprinting procedure, A and B have established a pairwise key. 3. Transitive PFP imprinting with nodes in PN: After the imprinting via intermediate node B, A can transitive imprint with all the other nodes in the PN, but first A has to discover B's imprinted nodes. The message sequence about the discovery can be found in Section 5.2. After this discovery, A establishes secure associations with these imprinted nodes and will continue to discover imprinted node and transitive imprint with them until A has trust relationships with all the possible nodes. 4. Initialization in the PN: After the establishment of secure connections, A is able to register itself into personal network. How this is exactly been accomplished is not in the scope of this report and therefore it will not be discussed.

Figure 11: Message sequence for the discovery of imprinted nodes. Node A is the initiator and T is the intermediate node and these nodes have a secure association with each other. The message sequence of the discovery of imprinted nodes is described below: First A scans the for nodes and retrieves a list of all the devices in the neighborhood and their corresponding addresses. 1. A must determine, which nodes are capable of transitive imprinting. A knows that T has the transitive imprinting service enabled and sends the message Req_TransIDS to node T. A -> T: Req_TransIDS (PKIDAT | E(PKAT, ADDRESSES) | HMAC(PKAT, PKIDAT | ADDRESSES)) This message is encrypted with the pairwise key between A and T, PKAT. The message contains the addresses with which A wishes to establish a secure association. These addresses corresponds to the nodes in the neighborhood. The type of addresses can be indicated by the message field ADDR_TYPE.

Page 36/45

Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics 2. When T retrieves the message Req_TransIDS, T decrypts the message and retrieves the addresses from the message. Subsequently T searches these addresses in the local database, whether it has already imprinted with these addresses or not. The result is the addresses / Magnet_ID pairs of the nodes, where T has imprinted with. In case there is an empty address field in the message and the field TOTALADDR is zero, T will reply with all the imprinted addresses and corresponding Magnet_ID pairs. Subsequently T returns the encrypted message Rsp_TransIDS. This message contains the address and Magnet_ID pairs retrieved by the local database. T -> A: RSP_TransIDS (PKIDAT | E(PKAT, RETIDS) | HMAC(PKAT ,PKIDAT | RETIDS) ) 3. A receives the message RSP_TransIDS, decrypts the message and retrieves the address / Magnet_ID pairs. A has now learned which nodes can do imprinting via intermediate node T. Assurance of the authenticity of the messages is achieved by appending a HMAC. The receiving node discards the message if the retrieved HMAC is not the same as the calculated HMAC. Advantages of discovery procedure described above is that:
The client, A is responsible for giving the addresses to T and T only returns these addresses and corresponding MAGNET_IDs. This discovery procedure is also used to map addresses to Magnet_IDs. Received addresses and corresponding Magnet_IDs are stored into A's local database such that A can do mapping between addresses and Magnet_IDs. When A wishes to transitive imprinting with for example node Z. A is not certain, which node can act as intermediate node with Z and therefore Z has to 'ask' the all imprinting nodes until it finds such intermediate node.

A disadvantage of this discovery procedure is that:
Message Sequence of transitive PFP imprinting
This section describes, the message sequence of the proposed PFP transitive imprinting procedure. The following assumptions have been made:
Node A and Node B are the nodes wanting to establish a secure association. Node T is the intermediate node with which A and B have already imprinted. The pair AT and the pair BT already have a secure assocation with each other B and T, have the service for transitive imprinting enabled. A, is a client that supports transitive imprinting.
Figure 12 illustrates the message sequence of transitive PFP imprinting and this message exchange is described below: Page 37/45
Experimental Analysis of a secure PFP Martijn Baars, Bachelor Thesis Telematics 1. A, the TPFP client, connects to node T and than T sends an empty Req_TransBegin message to A and the TPFP procedure is started. T -> A: Req_TransBegin() 2. A receives the empty Req_TransBegin message from T, generates a new nonce, Na and returns the message Resp_TransBegin. This message is encrypted with the key PKAT and contains the values: NA , the source and the destination Magnet_Ids (IDA and IDB) and A's public key (ga mod p). T -> A: Resp_TransBegin( PKIDAT | E(PKAT, IDA | IDB | NA ) | ga mod p | HMAC( PKAT , ga mod p) ) 3. T receives, decrypts the message and retrieves the IDs. 4. T checks if it has already imprinted with B and if so it maps the IDB into B's address and connects to the B's corresponding address. Subsequently B sends a empty Req_TransBegin message to T. B -> T: Req_TransBegin() 5. T forwards the unencrypted message Resp_TransBegin from A and encrypts it with the key of T and B, PKTB. T -> B: Resp_TransBegin( PKIDTB | E(PKTB, IDA | IDB | NA ) | ga mod p | HMAC( PKBT , ga mod p) ) 6. B receives the message Resp_TransBegin from T and retrieves the values from the message. Subsequently B generates a new nonce, NB, and can now calculate the temporary key between A and B, TKAB, according to Diffie-Hellman. Afterwards B generates a new permanent key from the nonces and the temporary key. (see Section 3.3, PFP key generation) 7. B replies the message Req_Transcont to T and this message contains B's nonce and also the B's public key. Subsequently A's nonce is added to the message for confirmation. Then the message is sendt by B and is forwarded by T in the same manner as the Resp_Transbegin message. B -> T: Req_TransCont( PKIDTB | E(PKTB , IDB | IDA | NA | NB ) | gb mod p | HMAC( PKBT , gb mod p) ) T -> A: Req_TransCont( PKIDTA | E(PKTA , IDB | IDA | NA | NB ) | gb mod p | HMAC( PKAT , gb mod p) ) 8. When A receives this Req_Transcont message, A can generate the temporary key TKAB and subsequently generates the permanent key PKAB in the same manner as B did. (see Section 3.3, key generation) 9. For confirmation of B's nonce, A indirectly sends via T the message Resp_TransCont and encrypts the nonce with the new generated permanent key, PKAB. A -> T: Resp_TransCont( PKIDAT | E(PKAT,IDA | IDB) | E(PKAB, NB ) ) T -> B: Resp_TransCont( PKIDBT | E(PKBT,IDA | IDB) | E(PKAB, NB ) ) 10. B receives the message and decrypts it with his newly generated permanent key, PKAB and checks if the receive nonce as the same as the B's nonce, which has been sent. Finally, B indirectly sends a EAP_Success message to A and the key-exchange is successfully ended. Page 38/45

Page 42/45

References
BlueZ - Official Linux Bluetooth protocol stack, http://www.bluez.org/, The Universal Operating System, http://www.debian.org/, Niels Ferguson and Bruce Schneier, Practical Cryptography, John Wiley & Sons, april 2003 GDK Reference Manual (GDK 2.6.10-1.osso11), https://stage.maemo.org/svn/maemo/projects/haf/doc/api/gdk/index.html GTK+ Reference Manual (GTK+ 2.6.10-1.osso11), https://stage.maemo.org/svn/maemo/projects/haf/doc/api/gtk/index.html Hildon Reference Manual (0.12.14), http://www.maemo.org/platform/docs/api-bora/hildon-docs/hildon-libs/index.html Christian Huitema, IPv6 The New Internet Protocol John Goerzen,Linux Programming Bible, April 2000, Hungry minds Application Development platform for Nokia Internet Tablet Products, http://www.maemo.org, IST - My personal Adaptive Global NET, http://www.ist-magnet.org/, Marina Pertova, Matthias Wellens, Simon Oosthoek, etc. , Overall secure PN architecture, MAGNET 2.1.2, 31st October 2005. Neeli Prasad, M. Imine, Sepideh Fouladgar, etc. , Implementation and Evaluation of the Level Security Architecture, MAGNET 4.3.3, December 31st 2005. E.F. Michels, Lecture Nodes Telematics System Security, University of Twente, November 2003
[BLUEZ] [DEBIAN] [FS-PC] [GDK] [GTK] [HILDON] [HU-NIPV6] [LPROG] [MAEMO] [MAGNET] [MD2.1.2] [MD4.3.3] [MI-TSS]
[NH-ADPN] I.G. Niemegeers and S.M. Heemstra de Groot, Research Issues in Ad-Hoc Distributed Personal Networks, Kluwer International Journal of Wireless and Personal Communications, Vol 26, No. 2-3, pp 149-167, 2003 [RFC 3748] [SBOX] B. Aloha, L. Blunk, J. Volbrecht and etc, Extensible Authentication Protocol (EAP), RFC 3748, June 2004 Scratchbox, http://www.scratchbox.org/,

Page 43/45

AES CLI GUI DH EAP GTK

List of Abbreviations

Advanced Encryption Standard Command Line Interface Graphical User Interface Diffie-Hellman Extensible Authentication Protocol The GIMP Toolkit The Keyed-Hash Message Authentication Code Internet Protocol Message Authentication Code Message Digest Algorithm 5 Network File System Request for Comments Rivest, Shamir, Adleman Proximity Authentication Channel Personal Area Network Personal Network Personal Area Network Formation Protocol Service Discovery Protocol Secure Hash Algorithm Secure Sockets Layer Transmission Control Protocol Transport Layer Security Temporary Key Transitive PFP

HMAC IP MAC MD5 NFS RFC RSA PAC PAN PN PFP SDP SHA SSL TCP TLS TK TPFP

Page 44/45

Appendix A: Notation Message Sequence
Description: a very large prime g is 2=<g=<p-2 Where the following properties must hold, such that: for every i, 1<i<=p-1 there must be a power j, that i=gj mod p holds. The private key of device A. The public key of device A. The Diffie Hellman shared key between devices A and B.

Notation: p g

a ga mod p gab mod p: or TKAB SHA1() SHA1(g mod p) or IDA SHA256() SHA256()32 NA:
160 bits hash function Magnet_ID, which is used to identify the devices
a 256-bits hash function. The first 32 bits of the 256-bits one-way hash function. Number used once, random value generated by A. When A and another device B, this value is used to generate a permanent key between A and B. Permanent key between A and B, is generated of NA ,NB and gab mod p. PKAB=SHA_256 (E(gab mod p , NA | NB) when NA<=NB or PKAB=SHA_256 (E(gab mod p , NB | NA) when NB<NA The identifier for the permanent key. It is used to identify the permanent key without publishing the key itself. The PKID is generated from NA NB, where NA and NB are used to generate the permanent key. PKIDAB=SHA_256 (NA , NB)32 when NA<=NB or PKIDAB=SHA_256 (NB , NA)32 when NB<=NA Conjunction of the messages M1, M2, M3. Messages M1,M2,M3 encrypted with key K. a hashed MAC encryption of message, M with key, K Message AnyMessage with data M1

PKIDAB

M1 | M2 | M3 E(K,M1|M2|M3) HMAC(M,K) AnyMessage(M1)

Page 45/45