公开(公告)号：CA1048935A

公开(公告)日：1979-02-20

申请号：CA243887

申请日：1976-01-20

Applicant: IBM

Inventor： EHRSAM WILLIAM F ,  MEYER CARL H ,  POWERS ROBERT L ,  PRENTICE PAUL N ,  SMITH JOHN L ,  TUCHMAN WALTER L

IPC: G09C1/00 ,  G06F21/22 ,  H04L9/06

Abstract: BLOCK CIPHER SYSTEM FOR DATA SECURITY A device for ciphering message blocks of data bits under control of a cipher key. The cipher device performs a ciphering process for the first half of the message block of data bits from a first store by carrying out an operation in which the block of data bits is expanded by duplicating predetermined ones of the data bits of the first half of the message block. The data bits of the expanded first half of said message block are combined by modulo-2 addition with an equal number of cipher key bits, selected in accordance with an arbitrary but fixed permutation, to produce a plurality of multi-bit segments forming the arguments for a plurality of different non-linear substitution function boxes. The substitution boxes perform a plurality of nonlinear transformation functions to produce a substitution set of bits which are equal in number to the number of data bits in the first half of the message block. The substitution of data bits is then subjected to a linear transformation in accordance with an arbitrary but fixed permutation. The combined non-linear transformation and linear transformation results in a product block cipher for the first half of the said message block. Then the second half of the message block from a second store is subjected to a linear transformation in accordance with the product block cipher to produce a set of bits representing a modified second half of said message block. Finally said modified second half of said message block is loaded into the first store and the first half of the message block from the first store is loaded into the second store concurrently with the modified second half of the message block being loaded into the first store to complete a first iteration operation of the cipher device.

公开(公告)号：CA1103358A

公开(公告)日：1981-06-16

申请号：CA314677

申请日：1978-10-30

Applicant: IBM

Inventor： MATYAS STEPHEN M ,  MEYER CARL H ,  TUCHMAN WALTER L

IPC: G09C1/00 ,  H04L9/32 ,  H04L9/00

Abstract: DIGITAL SIGNATURE SYSTEM AND APPARATUS A digital signature machine provides a simplified method of forming and verifying a signature that is appended to a digital message. A sender transmits a signature with the usual signature keys and with validation table entries that correspond to the unsent keys and with the compressed encoding of the next validation table. The receiver uses the compressed encoding of the next validation table to form validation table entries from the signature keys so that the receiver has a full validation table. This validation table is compressed and compared with the compressed encoding which was received from the sender in a preceding message.

公开(公告)号：CA1046942A

公开(公告)日：1979-01-23

申请号：CA243854

申请日：1976-01-20

Applicant: IBM

Inventor： EHRSAM WILLIAM F ,  MEYER CARL H ,  POWERS ROBERT L ,  SMITH JOHN L ,  TUCHMAN WALTER L

IPC: G09C1/00 ,  G06F21/22 ,  H04L9/06 ,  H04K1/00 ,  H04L9/02

Abstract: PRODUCT BLOCK CIPHER SYSTEM FOR DATA SECURITY A device for ciphering a block of data bits under control of a cipher key. The cipher device performs a ciphering process for the block of data by carrying out an operation in which the block of data bits is first expanded by duplicating predetermined ones of the data bits. The data bits of the expanded block are combined by modulo-2 addition with an equal number of cipher key bits, selected in accordance with an arbitrary but fixed permutation, to produce a plurality of multi-bit segments forming the arguments for a plurality of different nonlinear substitution function boxes. The substitution boxes perform a plurality of nonlinear transformation functions to produce a substitution set of bits which are equal in number to the number of data bits in the first half of the message block. The substitution set of bits is then subjected to a linear transformation in accordance with an arbitrary but fixed permutation. The combined nonlinear transformation and linear formation results in a product block cipher of the block of data.

公开(公告)号：CA1166712A

公开(公告)日：1984-05-01

申请号：CA380298

申请日：1981-06-22

Applicant: IBM

Inventor： MATYAS STEPHEN M ,  MEYER CARL H

IPC: H04K1/00 ,  H04L9/00

Abstract: CRYPTOGRAPHIC SYSTEM USING MULTIPLE ENCIPHERMENT Multiple encipherment under the DES algorithm is performed in three steps as an encipher/ decipher/ encipher sequence that gives the increased security of a longer key. The steps each use one of two keys of conventional length. When the two keys are the same, the operation is identical to a single encipherment under one key, and input quantities thus enciphered can be sent to a cryptographic facility that has only a single encipherment capability. The invention maintains compatability between users of multiple encipherment devices and users of single encipherment devices. The invention is particularly useful for enciphering keys and a detailed method and apparatus for this application is described.

公开(公告)号：CA1100588A

公开(公告)日：1981-05-05

申请号：CA275390

申请日：1977-03-30

Applicant: IBM

Inventor： EHRSAM WILLIAM F ,  MEYER CARL H ,  SMITH JOHN L ,  TUCHMAN WALTER L

IPC: G09C1/00 ,  G06F21/22 ,  H04L9/06 ,  H04L12/22 ,  H04L9/02

Abstract: MESSAGE VERIFICATION AND TRANSMISSION ERROR DETECTION BY BLOCK CHAINING A message transmission system for the secure transmission of multi-block data messages from a sending station to a receiving station. The sending station contains cryptographic apparatus operative in successive cycles of operation during each of which an input block of clear data bits is ciphered under control of an input set of cipher key bits to generate an output block of ciphered data bits for transmission to the receiving station. Included in the cryptographic apparatus of the sending station is means providing one of the inputs for each succeeding ciphering cycle of operation as a function of each preceding ciphering cycle of operation. As a result, each succeeding output block of ciphered data bits is effectively chained to all preceding cycles of operation of the cryptographic apparatus of the sending station and is a function of the corresponding input block of clear data -bits, all preceding input blocks of clear data bits and the initial input set of cipher key bits. KI9-74-013