ONEChat: an Efficient Group Chatting Platform for Opportunistic Networks Student: Heming Cui Master

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ONEChat an Efficient Group Chatting Platform for
Opportunistic NetworksStudent Heming
CuiMaster candidate at CS_at_CU
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Outline

• 1 Motivation
• 2 Two transmission modes in implementation
• 3 Security
• 4 File Transfer
• 5 Demo
• 6 Conclusion

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Outline

• 1 Motivation
• 2 Two transmission modes in implementation
• 3 Security
• 4 File Transfer
• 5 Demo
• 6 Conclusion

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1.1 Motivation

• Last semester, we proposes a group chatting
  application named ONEChat for opportunistic
  networks.
• mDNS is not a data transfer protocol.
• Three Improvements at this semester
• Real Time Text Replace current data distribution
  approach with real data transfer protocol.
• Improving its security.
• File transfer over RTP.

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1.2 ONEChat Framework
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Outline

• 1 Motivation
• 2 Two transmission modes in implementation
• 3 Security
• 4 File Transfer
• 5 Demo
• 6 Conclusion

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2.1 Message-by-message mode
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2.2 Char-by-char mode
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Outline

• 1 Motivation
• 2 Two transmission modes in implementation
• 3 Security
• 4 File Transfer
• 5 Demo
• 6 Conclusion

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3.1 Security for RTT messages

• 1 We use the GNU ZRTP4J library.
• 2 Use the SRTP-compatible libraries in ZRTP4J,
  actually AES and counter mode.
• 3 The key for each group is distributed by
  out-of-bound methods, e.g., secure email.
• All group messages/files within a group are
  encrypted/decrypted by a group key.
• Key verification mechanism to kick out malicious
  users.

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3.2 Key verification mechanism to kick out
malicious users(encryption/decryption are SRTP
compatible)
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Outline

• 1 Motivation
• 2 Two transmission modes in implementation
• 3 Security
• 4 File Transfer
• 5 Demo
• 6 Conclusion

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4 File Transfer

• File transfer is embedded in text transfer
  mechanism.
• Can transfer up to 64K bytes for each file.
• Two file transfer modes
• Updating buddy icon
• Normal file transfer

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4.1 Updating buddy icon
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4.2 Normal file transfer
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Outline

• 1 Motivation
• 2 Two transmission modes in implementation
• 3 Security
• 4 File Transfer
• 5 Demo
• 6 Conclusion

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Outline

• 1 Motivation
• 2 Two transmission modes in implementation
• 3 Security
• 4 File Transfer
• 5 Demo
• 6 Conclusion

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6 Conclusion

• Last semester, we proposes a group chatting
  application named ONEChat for opportunistic
  networks.
• Three Improvements at this semester
• Real Time Text Replace current data distribution
  approach with real data transfer protocol.
• Improving its security.
• File transfer over RTP.
• Next Step Write a technical paper (there is a
  previous version for the work at last semester).

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Thanks very much for your advice!?