| 5909494 |
System and method for constructing a cryptographic pseudo random bit generator |
| Jun-1-1999 |
A pseudo-random bit generator using at least one N-round Feistel construction that uses random functions. A block of data is permuted and divided into a stream word and a modification word. The stream... |
| 5852663 |
Information signal transmission system |
| Dec-22-1998 |
The information signal transmission system of the present invention is so designed as to convert the analog information signal into digital information data and to transmit these digital data after enciphering... |
| 5838794 |
Method and apparatus for inter-round mixing in iterated block substitution systems |
| Nov-17-1998 |
A method and apparatus for inter-round mixing in iterated block substitution systems is disclosed. The method involves optimizing inter-round mixing so that each sub-block of data affects each other in... |
| 5838796 |
Statistically optimized bit permutations in interated block substitution systems |
| Nov-17-1998 |
A method and apparatus for inter-round mixing in iterated block substitution systems is disclosed. The method involves optimizing inter-round mixing so that each data bit affects each other data bit in... |
| 5838795 |
Method and apparatus for statistical diffusion in iterated block substitution |
| Nov-17-1998 |
A method and apparatus for inter-round mixing in iterated block substitution systems is disclosed. The method involves optimizing inter-round mixing so that each sub-block of data affects each other in... |
| 5835600 |
Block encryption algorithm with data-dependent rotations |
| Nov-10-1998 |
A simple encryption and decryption device has been developed. The underlying algorithm is a fast block cipher that may be implemented efficiently in hardware or software. The algorithm makes heavy use... |
| 5835599 |
Muti-cycle non-parallel data encryption engine |
| Nov-10-1998 |
A multi-cycle, non-parallel DES encryption scheme that supports CBC, OFB, CFB, and ECB modes of operation. Three independent cipher stages are coupled together in series in order to implement a high-speed... |
| 5825886 |
Construction symmetric ciphers using the cast design procedure |
| Oct-20-1998 |
A new design procedure for constructing a family of DES-like Substitution-Permutation Network (SPN) cryptosystems with desirable cryptographic properties including provable resistance to differential cryptanalysis,... |
| 5818934 |
Method and apparatus for providing a cryptographically secure interface between the decryption engine and the system decoder of a digital television receiver |
| Oct-6-1998 |
A method for providing a secure interface between a decryption engine and a system decoder of a digital receiver, e.g., an MPEG-2 digital television receiver. The system decoder receives an encrypted bitstream... |
| 5815572 |
Video scrambling |
| Sep-29-1998 |
A system for scrambling a video signal, wherein multiple modes of scrambling are available, including (i) line reversal, (ii) line inversion, (iii) line permutation, and (iv) block permutation. The invention... |
| 5812955 |
Base station which relays cellular verification signals via a telephone wire network to verify a cellular radio telephone |
| Sep-22-1998 |
A secure radio personal communication system and method includes a base station which relays cellular verification signals between a wide area cellular network and a cellular terminal via the wire telephone... |
| 5812666 |
Cryptographic key management and validation system |
| Sep-22-1998 |
A Key Management System for generating, distributing and managing cryptographic keys used by an information transaction system that employs cryptographic means to produce evidence of information integrity.... |
| 5809148 |
Decryption of retransmitted data in an encrypted communication system |
| Sep-15-1998 |
The method generally includes the steps of receiving (201) a message (100) comprising a message indicator (101) and a plurality of encrypted blocks (103 through 111). When at least one block of the plurality... |
| 5799089 |
System and apparatus for blockwise encryption/decryption of data |
| Aug-25-1998 |
A system for encrypting and decrypting digital data wherein the data is divided in packets of N blocks X(1) . . . X(N) of 2.sup.m bits, comprises an encryption device and a decryption device. The encryption... |
| 5796837 |
Apparatus and method for generating a secure substitution-box immune to cryptanalyses |
| Aug-18-1998 |
The apparatus for generating a secure substitution-box immune to differential and linear cryptanalysises comprises a preprocessor for exchanging a location by the unit of bit while passing the input of... |
| 5796836 |
Scalable key agile cryptography |
| Aug-18-1998 |
A system and method for encrypting blocks of plain text. Output FIFO memories are provided for decoupling pseudorandom vector generation from plain text encryption. The output FIFOs produce the effect... |
| 5778074 |
Methods for generating variable S-boxes from arbitrary keys of arbitrary length including methods which allow rapid key changes |
| Jul-7-1998 |
A system for generating variable substitution boxes from arbitrary keys for use in a block cipher system utilizes an initial set of linearly independent numbers to generate substitution tables. The initial... |
| 5768390 |
Cryptographic system with masking |
| Jun-16-1998 |
A system for cryptographically transforming a sequence of input blocks of plaintext or ciphertext data into corresponding sequence of output blocks of data while providing enhanced protection against cryptographic... |
| 5757922 |
Method and system for packet scrambling communication with reduced processing overhead |
| May-26-1998 |
A packet scrambling communication scheme capable of reducing the processing amount and the processing time required for the scrambling processing and the descrambling processing at the transmitting side... |
| 5745577 |
Symmetric cryptographic system for data encryption |
| Apr-28-1998 |
A novel symmetric cryptographic system for data encryption uses two different sets of (m.times.n) s-boxes in its round function in one embodiment, where m and n are different integers. It also includes... |
| 5727062 |
Variable size block ciphers |
| Mar-10-1998 |
Data blocks of various size can be processed in fast, effective block cipher mechanisms. Variable size confusion layers and variable size diffusion layers combine to form variable size block ciphers. Block... |
| 5724428 |
Block encryption algorithm with data-dependent rotations |
| Mar-3-1998 |
A simple encryption and decryption device has been developed. The underlying algorithm is a fast block cipher that may be implemented efficiently in hardware or software. The algorithm makes heavy use... |
| 5694473 |
Decryption of retransmitted data in an encrypted communication system |
| Dec-2-1997 |
A method of decrypting retransmitted parts of a message includes receiving (201) a message comprising encryption synchronization and a plurality of encrypted blocks. Until a first block of the plurality... |
| 5687238 |
Small size product cipher apparatus |
| Nov-11-1997 |
In a product cipher apparatus, a permutation is performed upon plaintext or ciphertext to generate a first message. At least two successive substitutions are performed upon the first message to generate... |
| 5684876 |
Apparatus and method for cipher stealing when encrypting MPEG transport packets |
| Nov-4-1997 |
A method of encrypting clear payload data to form encrypted payload data uses a block cipher, the block cipher being characterized by a predetermined block length. The method includes a step of parsing... |
| 5682425 |
Information signal transmission system |
| Oct-28-1997 |
The information signal transmission system of the present invention is so designed as to convert the analog information signal into digital information data and to transmit these digital data after enciphering... |
| 5673321 |
Efficient selection and mixing of multiple sub-word items packed into two or more computer words |
| Sep-30-1997 |
A computer system facilitates efficient mixing of multiple sub-word items. Mixing circuitry is connected to a plurality of registers and a result register. The mixing circuitry mixes multiple sub-word... |
| 5673319 |
Block cipher mode of operation for secure, length-preserving encryption |
| Sep-30-1997 |
A method for encrypting a plaintext string into ciphertext begins by cipher block chaining (CBC) the plaintext using a first key and a null initialization vector to generate a CBC message authentication... |
| 5671283 |
Secure communication system with cross linked cryptographic codes |
| Sep-23-1997 |
A cryptographic communications system includes a method and apparatus for sending and receiving a plurality of encrypted signal packets in a system for metering the use of encrypted information. Plural... |
| 5661807 |
Authentication system using one-time passwords |
| Aug-26-1997 |
A system for authenticating a user located at a requesting node to a resource such as a host application located at an authenticating node using one-time passwords that change pseudorandomly with each... |
| 5659569 |
Data burst randomizer |
| Aug-19-1997 |
A method and system, for use in a communication system in which data is transmitted in data frames of a predetermined time duration, for the positioning of the data within the data frames for transmission.... |
| 5655021 |
Method for checking data sequences |
| Aug-5-1997 |
The invention relates to a method for checking data sequences, comprising a protection step and a verification step, with a control sequence being formed in the protection step on the basis of an identification... |
| 5652796 |
Data encryption control system |
| Jul-29-1997 |
The data encryption system includes a first stage and a second stage data encryption engine in combination with a micro control system. The data encryption system is responsive to control signals from... |
| 5647001 |
Nonlinear dynamic substitution devices and methods for block substitutions employing coset decompositions and direct geometric generation |
| Jul-8-1997 |
Methods and apparatus for non-linearizing modulo 2 addition based encryption by block substitution techniques which allows use of the substitution scheme with relatively simple hardware and yet makes cryptanalysis... |
| 5638448 |
Network with secure communications sessions |
| Jun-10-1997 |
A system which uses three way password authentication, and s.sup.3 DES to encrypt different portions of a logon packet with different keys based on the nature of the communications link. Nodes attached... |
| 5623549 |
Cipher mechanisms with fencing and balanced block mixing |
| Apr-22-1997 |
An enhanced cryptographic mechanism employs Latin square derived balanced size-preserving block mixers and strong, practical fencing arrays of substitution mechanisms in combination with each other and... |
| 5606616 |
Cryptographic apparatus with double feedforward hash function |
| Feb-25-1997 |
Apparatus is provided for authenticating information using a double feedforward hash function to provide complementarity in the implementation of an encryption algorithm. A cryptographic processor has... |
| 5604488 |
Remote control security system |
| Feb-18-1997 |
A remote control keyless security system for remotely controlling the locking and unlocking control functions of a lock mounted on a vehicle or the like. A receiver is mounted on a vehicle proximate to... |
| 5594797 |
Variable security level encryption |
| Jan-14-1997 |
A method and apparatus for digital cellular telephone encryption includes a switch when a choice between compatibility security and a higher security is required. Plaintext is converted into ciphertext... |
| 5548648 |
Encryption method and system |
| Aug-20-1996 |
The present invention provides a simple encryption method and system for encrypting data into a plurality of control and encrypted data blocks. The data to be encrypted is divided into data segments which... |
| 5546461 |
Scramble system for use in digital video signal recording and reproducing system or transmission and receiving system, comprising scramble apparatus and descramble apparatus |
| Aug-13-1996 |
A scramble system of the present invention including a scramble apparatus and a descramble apparatus is applied to a recording and reproducing system or a transmission and receiving system wherein a frame... |
| 5539827 |
Device and method for data encryption |
| Jul-23-1996 |
A cryptographic device and method provide a repertoire of mappings and associated inverse mappings between plaintext and ciphertext vectors. The plaintext is partitioned block-by-block, the block size... |
| 5533127 |
Encryption system |
| Jul-2-1996 |
A system for encrypting two-dimensional data such as image data, or data like multi-media data which can be transformed into two-dimensional data. The data is encrypted by multiple encryption passes through... |
| 5517614 |
Data compression/encryption processing apparatus |
| May-14-1996 |
A block processing section divides message data into a plurality of blocks, so as to obtain a plurality of data blocks. A plurality of data encryption processing sections are provided in correspondence... |
| 5432848 |
DES encryption and decryption unit with error checking |
| Jul-11-1995 |
An improved DES unit internally checks whether the DES algorithm is being performed without error. A standard DES algorithm performs an initial permutation of input data and then multiple rounds or iterations... |
| 5412729 |
Device and method for data encryption |
| May-2-1995 |
A cryptographic device and method provide a repertoire of mappings and associated inverse mappings between plaintext and ciphertext vectors. The plaintext is partitioned block-by-block, the block size... |
| 5404402 |
Clock frequency modulation for secure microprocessors |
| Apr-4-1995 |
A secure microprocessor is provided with reduced vulnerability to attack. In the past, the secure operation of such processors has been overcome by observing the behavior of the clock used by the processor.... |
| 5381480 |
System for translating encrypted data |
| Jan-10-1995 |
A system translates a first group of cipher blocks based on a first encryption key to a second group of respective cipher blocks based on a second encryption key. Respective cipher blocks of the first... |
| 5353352 |
Multiple access coding for radio communications |
| Oct-4-1994 |
Individual information signals encoded with a common block error-correction code are assigned a unique scrambling mask, or signature sequence, taken from a set of scrambling masks having selected correlation... |
| 5351299 |
Apparatus and method for data encryption with block selection keys and data encryption keys |
| Sep-27-1994 |
Disclosed is a data encryption apparatus strong to differential cryptanalysis, which is now the most influential cryptanalysis method. According to the data encryption apparatus, input data is divided... |
