METHOD FOR SECURELY EXTENDING KEY STREAM TO ENCRYPT HIGH-ENTROPY DATA
摘要
A stream stretcher is provided for securely expanding a key stream to match the length of a data block to be encrypted and/or decrypted. A key stream is obtained having a length of L<SUB>Z</SUB> bits. A length LD corresponding to a data block to be encrypted/decrypted is obtained, where L<SUB>D</SUB> > L<SUB>Z</SUB>. L<SUB>D</SUB>-L<SUB>Z</SUB> new bits are recursively generated by combining at least two bits of the key stream. The L<SUB>D</SUB>-L<SUB>Z</SUB> new bits are appended to the key stream to generate a stretched key stream. The data block may then be encrypted/decrypted with the stretched key stream. The at least two bits are selected to have offsets that form a full positive difference set.
申请公布号
WO2008049046(A2)
申请公布日期
2008.04.24
申请号
WO2007US81737
申请日期
2007.10.18
申请人
QUALCOMM INCORPORATED;ROSE, GREGORY GORDON;HAWKES, PHILIP MICHAEL