International Business Machines Corporation

Georgia Tech Research Corporation

Electronics and Telecommunications Research Institute

Korea Advanced Institute of Science and Technology

Demijan Klinc

Ashish Jagmohan

Hugo M Krawczyk

Tal D Rabin

Camit Hazay

Steven W McLaughlin

Dong Seung Kwon

Byung-Jae Kwak

Jeongseok Ha

A method, system and computer program product are disclosed for compressing encrypted data, wherein the data is encrypted by using a block encryption algorithm in a chained mode of operation, and the encrypted data is comprised of a set of N encrypted blocks, C. . . C. In one embodiment, the method comprises leaving block Cuncompressed, and compressing all of the blocks C. . . Cin a defined sequence using a Slepian-Wolf code. In an embodiment, the data is encrypted using an encryption key K, and the compressing includes compressing all of the blocks C. . . Cwithout using the encryption key. In one embodiment, the compressing includes outputting the blocks C. . . Cas a set of compressed blocks CmprC. . . CmprC, and the method further comprises decrypting Cto generate a reconstructed block {tilde over (X)}, and decrypting and decompressing the set of compressed blocks using {tilde over (X)}.

Compressing encrypted data without the encryption key

Compressing block-cipher encrypted data

A transmitter device (T) for secure communication includes: an encoder () configured to apply a non-systematic error correcting code (NS ECC) to a message, thus producing encoded bits with no clear message bits; and a transceiver () configured to transmit the encoded bits over a main channel to a receiver. A method for secure communication includes: encoding a message with an NS ECC to produce an encoded message carrying no message bits in the clear; and transmitting the encoded message over a main channel (). The NS ECC characteristics result in an eavesdropper channel error probability under a security threshold () and a main channel error probability over a reliability threshold (), whenever an eavesdropper () listening on an eavesdropper channel () is more than distance Z () from the transmitter. Unreliable bits in the encoded bits render the eavesdropper unable to reliably decode messages on the main channel.

Secure communication using non-systematic error control codes

Systems and methods for selecting a puncturing pattern for a low density parity check (LDPC) code are disclosed. One such method comprises: selecting a puncture pattern distribution for the LDPC code; calculating a security threshold and a reliability threshold for the LDPC, the LDPC having the selected puncture pattern distribution and also described by a degree distribution; storing the selected puncture pattern distribution responsive to a security gap for the LDPC being a lowest value encountered in any prior iterations; selecting another puncture pattern distribution for the LDPC code; and repeating the calculating, the storing, and the selecting another puncture pattern distribution steps.

Secure communication using error correction codes

A method, system and computer program product are disclosed for rateless compression of non-binary sources. In one embodiment, the method comprises representing a sequence of non-binary source symbols as a sequence of sets of binary values; selecting a code for compressing the sets of binary values; determining a puncturing pattern, based on the selected code; and puncturing the sets of binary values, in patterns based on the puncturing pattern, to form a sequence of unpunctured values. A sequence of computed syndromes is determined based on the sequence of non-binary source symbols; and the sequence of unpunctured values and the sequence of computed syndromes are combined to form an output stream of data representing said sequence of non-binary source symbols. In one embodiment, none of the sets of binary values is punctured completely, and, for example, each of the sets of binary values may be punctured only partially.

Efficient rateless distributed compression of non-binary sources

Growing community of inventors

Yorktown Heights, NY, United States of America

Demijan Klinc