CA2448907A1 - Method and apparatus to maintain encryption synchronization in a multi-modulation tdm system - Google Patents

Method and apparatus to maintain encryption synchronization in a multi-modulation tdm system Download PDF

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Publication number
CA2448907A1
CA2448907A1 CA002448907A CA2448907A CA2448907A1 CA 2448907 A1 CA2448907 A1 CA 2448907A1 CA 002448907 A CA002448907 A CA 002448907A CA 2448907 A CA2448907 A CA 2448907A CA 2448907 A1 CA2448907 A1 CA 2448907A1
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CA
Canada
Prior art keywords
bits
slot
receiving device
blocks
advancing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA002448907A
Other languages
French (fr)
Other versions
CA2448907C (en
Inventor
Robert D. Logalbo
Alan Conrad
Darrell Stogner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Motorola Solutions Inc
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2448907A1 publication Critical patent/CA2448907A1/en
Application granted granted Critical
Publication of CA2448907C publication Critical patent/CA2448907C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/06—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols the encryption apparatus using shift registers or memories for block-wise or stream coding, e.g. DES systems or RC4; Hash functions; Pseudorandom sequence generators
    • H04L9/065—Encryption by serially and continuously modifying data stream elements, e.g. stream cipher systems, RC4, SEAL or A5/3
    • H04L9/0656—Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher
    • H04L9/0662—Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher with particular pseudorandom sequence generator
    • H04L9/0668—Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher with particular pseudorandom sequence generator producing a non-linear pseudorandom sequence
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/12—Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L2209/00—Additional information or applications relating to cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
    • H04L2209/80—Wireless

Abstract

Encryption synchronization (e-sync) is maintained between a transmitter (104 ) and one or more receivers (102) in a multi-modulation TDM system (100) where information is communicated in slots (402) comprising a slot header (404) an d one or more data blocks (406), and wherein the data blocks are eligible to b e encoded at different modulation rates thereby creating a likelihood of different numbers of blocks in different slots. The receiver and transmitter employ respective encryption elements (200, 300) comprising e-sync shifter elements (202, 302) and encryption algorithm blocks (204, 304). The e-sync shifter element provides an e-sync signal defining an encryption state vecto r to the encryption algorithm block and is operable to advance the encryption state vector (in the case of the receiver) according to a number of received bits plus a variable number of bits.

Claims (10)

1. A method for a receiving device to maintain encryption synchronization in a multi-modulation TDM system whereby information is communicated in slots comprising a slot header and one or more data blocks, the data blocks each including a number of bits (N B) and being eligible to be encoded at different respective modulation rates thereby creating a likelihood of different numbers of blocks in different slots, the method comprising:
attempting, by the receiving device, to determine a number of blocks (B) in at least a first received slot;
if the receiving device can not determine the number of blocks (B) in the first slot, determining a maximum number of blocks (B MAX) that could be within the slot; and advancing an encryption state of the receiving device a number of bits (N B × B MAX).
2. The method of claim 1, wherein the step of attempting to determine the number of blocks (B) in at least a first slot comprises attempting to decode the slot header of the first slot, wherein the slot header defines at least the number of blocks (B) in the first slot.
3. The method of claim 1, wherein the step of determining a maximum number of blocks (B MAX) that could be within the slot comprises:
determining a maximum modulation rate that is eligible to be used within the slot; and determining a number of blocks that would occur in the slot corresponding to the maximum modulation rate.
4. The method of claim 1, wherein the step of advancing the encryption state of the receiving device the number of bits (N B × B MAX) comprises:
decoding, by the receiving device, N B × B MAX bits; and advancing a shift register in an encryption device associated with the receiving device, a number of bits corresponding to the N B × B MAX bits.
5. The method of claim 1, further comprising, if the receiving device determines the number of blocks (B) in the first slot, steps of:
advancing the encryption state of the receiving device B × N B bits, thereby corresponding to the number of bits in the first slot; and advancing the encryption state N B × (B MAX - B) bits defining a shift of zero or more bits in addition to the number of bits in the first slot.
6. The method of claim 5, wherein the step of advancing the encryption state N B × (B MAX - B) bits is accomplished after the step of advancing the encryption state of the receiving device B × N B bits.
7. The method of claim 5, wherein the step of advancing the encryption state N B × (B MAX - B) bits is accomplished prior to the step of advancing the encryption state of the receiving device B × N B bits.
8. The method of claim 5, wherein the step of advancing the encryption state of the receiving device B × N B bits comprises:
for each consecutive block, generating N B bits, and advancing a shift register corresponding to the N B bits.
9. The method of claim 8, further comprising:
for each consecutive block, attempting to determine a targeted recipient of the block; and if the receiving device can not determine the targeted recipient of a block, discarding the block and the N B bits generated for the block.
10. The method of claim 9, further comprising:
if the receiving device determines itself not to be the targeted recipient of a block, discarding the block and the N B bits generated for the block.
CA2448907A 2002-03-29 2002-11-25 Method and apparatus to maintain encryption synchronization in a multi-modulation tdm system Expired - Fee Related CA2448907C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US10/112,990 2002-03-29
US10/112,990 US7095856B2 (en) 2002-03-29 2002-03-29 Method and apparatus to maintain encryption synchronization in a multi-modulation TDM system
PCT/US2002/037829 WO2003085870A1 (en) 2002-03-29 2002-11-25 Method and apparatus to maintain encryption synchronization in a multi-modulation tdm system

Publications (2)

Publication Number Publication Date
CA2448907A1 true CA2448907A1 (en) 2003-10-16
CA2448907C CA2448907C (en) 2010-07-20

Family

ID=28453477

Family Applications (1)

Application Number Title Priority Date Filing Date
CA2448907A Expired - Fee Related CA2448907C (en) 2002-03-29 2002-11-25 Method and apparatus to maintain encryption synchronization in a multi-modulation tdm system

Country Status (6)

Country Link
US (1) US7095856B2 (en)
EP (1) EP1490992A4 (en)
AU (1) AU2002352916A1 (en)
CA (1) CA2448907C (en)
IL (1) IL159020A0 (en)
WO (1) WO2003085870A1 (en)

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US8218768B2 (en) * 2002-01-14 2012-07-10 Qualcomm Incorporated Cryptosync design for a wireless communication system
SI1513279T1 (en) * 2003-09-08 2008-04-30 Abb Research Ltd Data encryption on the physical layer of a data transmission system
US7801297B2 (en) * 2003-11-20 2010-09-21 Ntt Docomo, Inc. Communication device and communication control method
CN100525498C (en) * 2004-03-24 2009-08-05 摩托罗拉公司 Method and device for call encryption
US7620181B2 (en) * 2005-04-20 2009-11-17 Harris Corporation Communications system with minimum error cryptographic resynchronization
DE102005031611B4 (en) * 2005-07-06 2007-11-22 Infineon Technologies Ag Proof of a change in the data of a data record
US8582767B1 (en) 2010-09-27 2013-11-12 Charles C. Hardy Cryptographic device sharing among a plurality of communication links
JP2013005293A (en) * 2011-06-17 2013-01-07 Toshiba Corp Authentication component, authentication target component, and authentication method for the same
US9449183B2 (en) * 2012-01-28 2016-09-20 Jianqing Wu Secure file drawer and safe

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US4642424A (en) * 1984-01-03 1987-02-10 At&T Information Systems Inc. Cryptographic transmission system
US4803726A (en) * 1986-12-31 1989-02-07 Motorola, Inc. Bit synchronization method for a digital radio telephone system
US4928274A (en) * 1988-01-19 1990-05-22 Qualcomm, Inc. Multiplexed address control in a TDM communication system
SE465797B (en) * 1990-03-07 1991-10-28 Ericsson Telefon Ab L M PROCEDURE TO TRANSFER SYNCHRONIZATION INFORMATION FOR CRYPED TRANSFER IN A MOBILE RADIO SYSTEM
US5161189A (en) * 1991-03-11 1992-11-03 Motorola, Inc. Encryption and decryption of chained messages
US5222142A (en) * 1992-06-22 1993-06-22 Hughes Aircraft Company Sequence generator
GB9418750D0 (en) * 1994-09-16 1994-11-02 Ionica L3 Limited Digital telephony
US5694473A (en) * 1996-05-17 1997-12-02 Motorola, Inc. Decryption of retransmitted data in an encrypted communication system
US5825889A (en) * 1996-10-15 1998-10-20 Ericsson Inc. Use of duplex cipher algorithms for satellite channels with delay
US6081600A (en) * 1997-10-03 2000-06-27 Motorola, Inc. Method and apparatus for signaling privacy in personal communications systems
US6778558B2 (en) * 1998-02-23 2004-08-17 Lucent Technologies Inc. System and method for incremental redundancy transmission in a communication system
US6798791B1 (en) * 1999-12-16 2004-09-28 Agere Systems Inc Cluster frame synchronization scheme for a satellite digital audio radio system
US7003114B1 (en) * 2000-01-20 2006-02-21 Qualcomm Incorporated Method and apparatus for achieving crypto-synchronization in a packet data communication system
US6567387B1 (en) * 2000-11-07 2003-05-20 Intel Corporation System and method for data transmission from multiple wireless base transceiver stations to a subscriber unit
US7436964B2 (en) * 2000-12-19 2008-10-14 At&T Mobility Ii Llc Synchronization of encryption in a wireless communication system
US8218768B2 (en) * 2002-01-14 2012-07-10 Qualcomm Incorporated Cryptosync design for a wireless communication system
US6795419B2 (en) * 2002-03-13 2004-09-21 Nokia Corporation Wireless telecommunications system using multislot channel allocation for multimedia broadcast/multicast service

Also Published As

Publication number Publication date
EP1490992A4 (en) 2006-06-07
IL159020A0 (en) 2004-05-12
CA2448907C (en) 2010-07-20
WO2003085870A1 (en) 2003-10-16
AU2002352916A1 (en) 2003-10-20
US7095856B2 (en) 2006-08-22
EP1490992A1 (en) 2004-12-29
US20030188148A1 (en) 2003-10-02

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