Method and apparatus to provide encryption and authentication of a mini-packet in a multiplexed RTP payload

• US 6,918,034 B1
• Filed: 09/29/1999
• Issued: 07/12/2005
• Est. Priority Date: 09/29/1999
• Status: Expired due to Fees

• Current Assignee: Nokia Networks (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Subbiah, Baranitharan, Sengodan, Senthil
• Primary Examiner(s): Morse, Gregory
• Assistant Examiner(s): Tran, Tongoc
• Application Number:
  US09/408,567
• Time in Patent Office: 2,113 Days
• Field of Search: 713150-153, 713160-161, 370/473, 370/474, 370/505, 370/476
• US Class Current: 713/160
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32

Abstract

A method and apparatus to provide encryption and authentication of a mini-packet in a multiplexed real time protocol (RTP) payload. Mini-packets are assembled into a payload wherein each mini-packet includes an associated mini-header for ensuring proper processing of each mini-packet. Padding is added to mini-packets when the mini-packets are encrypted to insure each mini-packet is an integral multiple of a predetermined block size. Padding for each mini-packet is determined according to p=n−k*floor((n−1)/k), wherein p is the amount of padding added to each mini-packet, n is the actual data size, and k is the block size. The padding added to the data for each packet comprises p−1 units of padding and a final padding unit for indicating the amount of padding. An authenticator may also be added to each mini-packet. A length indicator is set in each mini-header for indicating a total length of the mini-packet including the authenticator. The authenticator may then be removed based upon knowing a type of authentication used for generating the authenticator.

Claims

1. A mini-packet protocol comprising:

assembling mini-packets into a payload wherein each mini-packet includes an associated mini-header for ensuring proper processing of each mini-packet; and

adding padding to mini-packets when the mini-packets are encrypted to insure each mini-packet is an integral multiple of a predetermined block size,

wherein padding for each min-packet is determined according to;

p=n−

k*floor(n−

1)/k),

wherein p is the amount of padding added to each mini-packet, n is the actual data size, and k is the block size.

2. The mini-packet protocol of claim 1 wherein the padding added to the data for each packet comprises p−

1 units of padding and a final padding unit for indicating the amount of padding.

3. The mini-packet protocol of claim 2 wherein the unit is bytes.

4. The mini-packet protocol of claim 1 further comprising adding an authenticator to each mini-packet.

5. The mini-packet protocol of claim 4 further comprising setting a length indicator in each mini-header for indicating a total length of the mini-packet including the authenticator.

6. The mini-packet protocol of claim 5 further comprising removing the authenticator based upon knowing a type of authentication used for generating the authenticator.

7. The mini-packet protocol of claim 6 wherein the type of authentication comprises HMAC-SHA1 and the authenticator is 20 bytes.

8. The mini-packet protocol of claim 6 wherein the type of authentication comprises HMAC-MD5 and the authenticator is 16 bytes.

25. The mini-packet protocol of claim 1, wherein said adding step comprises adding the padding to the mini-packets, in which the padding varies from 1 to the predetermined block size.

9. A mini-packet controller comprising:

a disassembler for receiving a payload, the payload including a plurality of mini-packets, wherein the disassembler dismantles the payload into individual mini-packets;

a controller and signaling module, coupled to the disassembler, for processing the individual mini-packets, the controller further assembling the individual mini-packets into a payload wherein each mini-packet includes an associated mini-header for ensuring proper processing of each mini-packet and adding padding to mini-packets when the mini-packets are encrypted to insure each mini-packet is an integral multiple of a predetermined block size; and

an assembler for combining mini-packets into a new payload for transmission via an output port,

wherein the padding for each mini-packet is determined according to;

p=n−

k*floor(n−

1)/k),

wherein p is the amount of padding added to each mini-packet, n is the actual data size, and k is the block size.

10. The mini-packet controller of claim 9 wherein the added padding for each packet comprises p−

1 units of padding and a final padding unit for indicating the amount of padding.

11. The mini-packet controller of claim 10 wherein the units are bytes.

12. The mini-packet controller of claim 9 wherein the controller and signaling module adds an authenticator to each mini-packet.

13. The mini-packet controller of claim 12 wherein the controller sets a length indicator in each mini-header for indicating a total length of the mini-packet including the authenticator.

14. The mini-packet controller of claim 13 wherein the controller and signaling module removes authenticators based upon knowing a type of authentication used for generating an authenticator.

15. The mini-packet controller of claim 14 wherein the type of authentication comprises HMAC-SHA1 and the authenticator is 20 bytes.

16. The mini-packet controller of claim 14 wherein the type of authentication comprises HMAC-MD5 and the authenticator is 16 bytes.

26. The mini-packet controller of claim 9, wherein the padding varies from 1 to the predetermined block size.

17. An article of manufacture comprising a computer readable medium having instructions for causing a computer to perform a method comprising:

assembling mini-packets into a payload wherein each mini-packet includes an associated mini-header for ensuring proper processing of each mini-packet; and

adding padding to mini-packets when the mini-packets are encrypted to insure each mini-packet is an integral multiple of a predetermined block size,

wherein padding for each mini-packet is determined according to;

p=n−

k*floor(n−

1/k),

wherein p is the amount of padding added to each mini-packet, n is the actual data size, and k is the block size.

18. The article of manufacture of claim 17 wherein the padding added to the data for each packet comprises p−

1 units of padding and a final padding unit for indicating the amount of padding.

19. The article of manufacture of claim 18 wherein the unit is bytes.

20. The article of manufacture of claim 17 further comprising adding an authenticator to each mini-packet.

21. The article of manufacture of claim 20 further comprising setting a length indicator in each mini-header for indicating a total length of the mini-packet including the authenticator.

22. The article of manufacture of claim 21 further comprising removing the authenticator based upon knowing a type of authentication used for generating the authenticator.

23. The article of manufacture of claim 22 wherein types of authentication comprises HMAC-SHA1 and the authenticator is 20 bytes.

24. The article of manufacture of claim 22 wherein the type of authentication comprises HMAC-MD5 and the authenticator is 16 bytes.

27. The article of manufacture of claim 17, wherein said adding step comprises adding the padding to the mini-packets, in which the padding varies from 1 to the predetermined block size.