Matches 301 - 344 out of 344 < 1 2 3 4 5 6 7
Match Document Document Title
4852165 Secure system and method for providing personal identifier  
The invention pertains to apparatus and methods for securely transmitting a personal identifier between an originator thereof and a preselected data base. Especially, pertaining to a computer...
4850019 Data randomization equipment  
Input data is split by a splitting part into a plurality of block data having an equal data length to be processed through respective channels. Each channel data is subjected in a function...
4825050 Security transaction system for financial data  
A system for a data protection executing financial transactions employing cryptographic techniques. The system comprises an encoded card, which has been initially encrypted using the National...
4823388 Communications network using an enciphering and deciphering device  
A communications network system is constructed by connecting a plurality of customer terminals to one central terminal via communication lines. Enciphering devices and a deciphering device, such as...
4804825 I C card system  
An IC card system in which either an on-line transaction or an off-line transaction can be made by using an IC card. The IC card contains a memory for storing the data about every transaction made...
4802217 Method and apparatus for securing access to a computer facility  
A security unit is disclosed for controlling access to a main computer system. The security unit provides a comprehensive mechanism for detecting and inhibiting sophisticated attackers. A method of...
4797928 Encryption printed circuit board  
An encryption printed circuit board (PCB) for use as an add on board to a host computer includes address registers, read/write controller, and data information transceiver adapted for connection to...
4792973 Selective enablement of descramblers  
A system in a subscriber television network for enabling descrambling of a received scrambled signal on a prepaid basis and/or an impulse-purchase basis. A received mask signal uniquely related to...
4731843 Method and device of increasing the execution speed of cipher feedback mode of the DES by an arbitrary multiplier  
In an encryption system comprising DES in a cipher feedback mode of k bits, a plain text bit stream is fed into n individual DES encryptors. The DES encryptor operates in parallel from a common...
4727476 Simulation and security device for data entry keyboard  
A simulation security device for a data entry keyboard of a computer is operative with an input-output unit and a keyboard of the computer. The device includes plural memories and a switching...
4712238 Selective-subscription descrambling  
A system in a subscriber television network for enabling descrambling of a received scrambled signal on a prepaid basis and/or an impulse-purchase basis. A received mask signal uniquely related to...
4645871 Non-interfering in-band protocol-independent diagnostic scanning in a digital multipoint communication system  
In a system in which data between a master and remote location is encrypted by using the DES algorithm, the status of security devices at the remote location is monitored from a centralized...
4634807 Software protection device  
In order to prevent the unauthorized copying of software, a software module is encrypted using the data encryption standard (DES) algorithm, and the key is encrypted using the public key of a...
4634808 Descrambler subscriber key production system utilizing key seeds stored in descrambler  
A system for reproducing in a descrambler of a subscriber communication network a subscriber key signal that is unique to the descrambler and was used in encrypting a key signal that must be...
4613901 Signal encryption and distribution system for controlling scrambling and selective remote descrambling of television signals  
A system and method for scrambling and selectively descrambling television signals that are transmitted to subscribers' descramblers in a subscription television system. A working key signal is...
4591660 Common control audio decryptor  
Decryption of a plurality of simultaneously received, randomly phased signals is realized by employing a single data encryption standard module in a time shared manner. A plurality of process state...
4578530 End-to-end encryption system and method of operation  
An efficient end-to-end encryption system including key management procedures for providing secure, financial data communication between a system user at one of a plurality of transaction terminals...
4558176 Computer systems to inhibit unauthorized copying, unauthorized usage, and automated cracking of protected software  
A method and apparatus are provided for inhibiting unauthorized copying, unauthorized usage and automated cracking of proprietary software used in computer systems. The computer systems execute...
4543646 Chip topography for MOS Data Encryption Standard circuit  
An optimum chip topography for a MOS LSI Data Encryption Standard (DES) circuit, including interface and input/output circuitry disposed around the periphery of the chip, control circuitry disposed...
4520232 Polygraphic encryption-decryption system  
A system for encoding, or encrypting, digital data wherein an invertible matrix of binary bits provides the encrypting factor or key, this invertible matrix being loaded in a memory. Blocks or sets...
4438824 Apparatus and method for cryptographic identity verification  
The apparatus for identity verification using a data card contains at least one terminal and a security service station. The terminal(s) and the station are connected to each other via a...
4369332 Key variable generator for an encryption/decryption device  
An apparatus and method for generating a unique working key variable for controlling the operation of an encryption/decryption device during each user specified time period. The apparatus generates...
4352952 Data security module  
A data security module for encrypting and decrypting computer data contains, in addition to the encryption logic, interface logic to allow direct memory access to a computer. The security module...
RE30957 Variant key matrix cipher system  
This is a cipher system for enciphering a stream of binary data by means of a product cipher. A clear message represented in a binary data format is transformed into a cipher message by operating...
4326098 High security system for electronic signature verification  
The system provides both electronic signature and message verification with a minimum of excess coding information on an instantaneous basis and is easily restartable in a store and forward...
4322577 Cryptosystem  
Encryption and decryption of information of a message is performed by partitioning a plaintext message into blocks of binary digits and by further partitioning said blocks into subblocks which are...
4322576 Message format for secure communication over data links  
Communication over data links using binary synchronous protocol that is to be made secure according to the Federal data encryption standard (DES) is enhanced by utilizing an encrypted message...
4275265 Complete substitution permutation enciphering and deciphering circuit  
A complete substitution permutation enciphering and deciphering circuit and method for transforming a plaintext signal into an enciphered signal which is secure during transmission. After receipt,...
4274085 Flexible mode DES system  
A DES (Data Encryption Standard) system utilizing an input register, control logic and output register to provide for a selection from a multiplicity of operable modes on a single chip or family of...
4262358 DES Parity check system  
A system for providing on-line parity checking in data encryption/decryption systems such as DES and which is especially useful where multiple stage shifting is accomplished on a single clock input...
4249180 Past dependent microcomputer cipher apparatus  
Apparatus for use in a secure data communication system includes a microcomputer that controls a cipher process by which sensitive data is encrypted before transmission. When activated, the...
4203166 Cryptographic file security for multiple domain networks  
A file security system for data files created at a first host system in one domain and recovered at a second host system in another domain of a multiple domain network. Each of said host systems...
4195200 Key controlled block-cipher cryptographic system employing a multidirectional shift matrix  
A cryptographic system for enciphering a block of binary data under the control of a unique key consisting of a set of binary symbols. A clear message represented in binary data format is...
4177355 Array device for data scrambling  
This specification describes an array logic chip that can be used to encipher and decipher binary data. The array logic chip contains a matrix of input and output lines with the input lines divided...
4172213 Byte stream selective encryption/decryption device  
An apparatus for insertion in a communications line for providing message secrecy within a significant portion of existing communications networks. At the transmitter end, the apparatus receives...
4160120 Link encryption device  
An apparatus for insertion in a communications line for providing both message integrity and message secrecy within a significant portion of existing communications networks. At the transmitter...
4123747 Identity verification method and apparatus  
An improved method for verifying the identity of a prospective terminal user presenting an identification card or a credit card and a memorized personal identification number. Only part of the...
4074066 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...
4004089 Programmable cryptic device for enciphering and deciphering data  
An encrypter for encoding and decoding data, wherein clear text data to be encoded is logically combined with a portion of a non-linear pseudo-random bit sequence signal to provide a partially...
3962539 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...
3958081 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 an enciphering process for each message block of data by carrying out a predetermined...
3798360 STEP CODE CIPHERING SYSTEM  
This specification discloses a system that provides multiple level encipherment of a block of data by means of a stepped block cipher process. A data stream consisting of digital information is...
3798359 BLOCK CIPHER CRYPTOGRAPHIC SYSTEM  
A cryptographic system for encrypting a block of binary data under the control of a key consisting of a set of binary symbols. The cryptographic system is utilized within a data processing...
3796830 RECIRCULATING BLOCK CIPHER CRYPTOGRAPHIC SYSTEM  
This is a cryptographic system for enciphering a block of binary data under the control of a subscriber cipher key consisting of a preassigned combination of binary symbols. The block of data is...
Matches 301 - 344 out of 344 < 1 2 3 4 5 6 7