Matches 201 - 250 out of 344 < 1 2 3 4 5 6 7 >
Match Document Document Title
5793659 Method of modular reduction and modular reduction circuit  
A method of modular reduction P mod Q based on a precomputation. Two quantities are precomputed and stored in a look-up table. Based on these stored precomputed quantities, two stages of partial...
5778067 Value transfer system  
A value transfer system which allows value to be transferred between electronic purses comprises computer which controls the loading of purses with value and the redemption of value from purses, a...
5768390 Cryptographic system with masking  
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...
5764762 Encrypted data package record for use in remote transaction metered data system  
The disclosed system relates to metered use cryptographic systems, and particularly to a data package and system operation for effecting metered purchases of encrypted data from a local encrypted...
5757913 Method and apparatus for data authentication in a data communication environment  
A method and system for providing data authentication, within a data communication environment, in a manner which is simple, fast, and provably secure. A data message to be sent is partitioned into...
5745577 Symmetric cryptographic system for data encryption  
A novel symmetric cryptographic system for data encryption uses two different sets of (m×n) s-boxes in its round function in one embodiment, where m and n are different integers. It also includes...
5734718 NIS+ password update protocol  
The present invention provides methods and apparatus for updating passwords in a name service system. A server includes a name service database that further includes a plurality of tables with...
5717759 Method for certifying public keys in a digital signature scheme  
A method for certifying public keys of a digital signature scheme in a communications system is provided. The secure communications system is one in which there are at least two levels of...
5696829 Digital postage meter system  
A mailing system is includes of a mailing machine operating under the control of a microcontroller having a communication port with a first channel and a second channel. The mailing system also...
5689566 Network with secure communications sessions  
A system which uses three way password authentication, encrypting different portions of a logon packet with different keys based on the nature of the communications link. Nodes attached to a...
5687238 Small size product cipher apparatus  
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...
5687237 Encryption key management system for an integrated circuit  
A microcontroller is in bus communication with an improved integrated circuit for providing data to the integrated circuit and reading data from the integrated circuit. The integrated circuit...
5684876 Apparatus and method for cipher stealing when encrypting MPEG transport packets  
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...
5675650 Controlled acceptance mail payment and evidencing system  
A method for controlled acceptance mail payment and evidencing in accordance with the present invention includes creating a mail batch with a plurality of mailpieces each having encrypted indicia...
5675652 Computer readable device implementing a software-efficient pseudorandom function encryption  
A software-efficient pseudorandom function maps an index and an encryption key to a pseudorandom bit string useful for constructing a stream cipher. The method begins by preprocessing the...
5671279 Electronic commerce using a secure courier system  
A courier electronic payment system provides customers, merchants, and banks with a secure mechanism for using a public network as a platform for credit card payment services. The system governs...
5671284 Data encryptor having a scalable clock  
A method for encrypting and decrypting digital data. The digital data is initially latched by an input register. Sixteen separate cipher stages cascaded in series are used to encrypt the digital...
5671283 Secure communication system with cross linked cryptographic codes  
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....
5668880 Inter-vehicle personal data communications device  
A device for wireless, secure transmission of digital information signals utilizing carrier sense multiple access (CSMA) packet communications, or spread spectrum code division multiple access...
5664016 Method of building fast MACS from hash functions  
Hash functions are important in modern cryptography. Main applications are their use in conjunction with digital signature schemes and message authentication. Hash functions, commonly known as...
5661807 Authentication system using one-time passwords  
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...
5652796 Data encryption control system  
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...
5652793 Method and apparatus for authenticating the use of software  
A hardware encoding circuit which generates a code value unique to a particular computer, stores a password unique to an application program and to the particular computer, tests the stored...
5647001 Nonlinear dynamic substitution devices and methods for block substitutions employing coset decompositions and direct geometric generation  
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...
5638450 Method and apparatus for establishing two way communications between a pager device and a paging service provider  
A two way communications path is established between a pager device and a paging service provider. The pager device generates a control command for the paging service provider, converts the control...
5625695 Process for generating DSA signatures with low-cost portable apparatuses  
The invention relates to a process for generating digital signatures from portable apparatuses (A1, A2, . . . Ai . . . An) of the microprocessor-based card type, including means for computation,...
5623548 Transformation pattern generating device and encryption function device  
In accordance with the present invention, there is provided a transformation pattern generating mechanism comprising: a key input section for inputting a key for encryption; a transformation...
5621796 Transferring information between transaction networks  
A stored value transaction system has a plurality of value storing transfer devices. First and second stored value transaction networks each include at least one local value storing device, at...
5610982 Compact certification with threshold signatures  
Certifying data includes having a subgroup of authorities each contribute a partial digital signature of the data to enable computation of a combined signature where the subgroup includes some, but...
5608801 Efficient cryptographic hash functions and methods for amplifying the security of hash functions and pseudo-random functions  
Methods and circuitry for generating a cryptographic hash function using a strong pseudo-random generator along with the input data to create high quality pseudo-random keys as indices to...
5606616 Cryptographic apparatus with double feedforward hash function  
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...
5592555 Wireless communications privacy method and system  
A method and system for privately communicating signals over a wireless communications network include the steps of and circuitry and instructions for processing communication signals in a first...
RE35403 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...
5584022 Enciphered file sharing method  
An enciphered file sharing method is adapted to an area distributed type data processing system in which a plurality of data processing units are coupled via a network and a plurality of users...
5583940 Method, apparatus and device for enciphering messages transmitted between interconnected networks  
A method of enciphering messages transmitted between at least two networks (2, 17) interconnected via at least one highway (8), the interconnected networks (2, 17) using the Internet protocol (IP,...
5574860 Method of neighbor discovery over a multiaccess nonbroadcast medium  
A technique for generating, distributing and maintaining a list of operational nodes in a network using a nonbroadcast communication medium, wherein the nodes first collectively agree on the...
5548648 Encryption method and system  
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...
5539827 Device and method for data encryption  
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...
5513262 Device for enciphering and deciphering, by means of the DES algorithm, data to be written to be read from a hard disk  
A device for enciphering and deciphering with the aid of the DES algorithm data to be written to or read from a hard disk, wherein the input of a DES cipher device (25) is coupled, via a converter...
5511123 Symmetric cryptographic system for data encryption  
A novel symmetric cryptographic system for data encryption using novel partially bent-function-based (m×n) substitution boxes (s-boxes), where m and n are positive even numbers, m<<n and...
5493613 Combination pin pad and terminal  
A secure terminal is disclosed which has a single keypad and display which is suitable as a debit terminal, as both confidential and nonconfidential information can be entered. Confidential...
5488661 Data communication system and method with data scrambling  
Data communication system and method with a data scrambling with high security. A data scrambling part is provided with a extended key memory for storing addresses of extended keys, and one of the...
5473693 Apparatus for avoiding complementarity in an encryption algorithm  
An implementation of a security algorithm such as DES is provided that overcomes the complementarity weaknesses provided by conventional implementations. In a DES implementation, a cryptographic...
5452358 Method and apparatus for improving the security of an electronic codebook encryption scheme utilizing a data dependent encryption function  
An apparatus and method for improving the security of an electronic codebook encryption scheme comprises a transmitter unit for encoding or encrypting data and a separate authorized receiver for...
5442645 Method for checking the integrity of a program or data, and apparatus for implementing this method  
The invention relates to a method and apparatus for checking the integrity of a message such as a program and/or data against an original message supposed to correspond to it. By using an algorithm...
5442705 Hardware arrangement for enciphering bit blocks while renewing a key at each iteration  
A plaintext is enciphered using a plurality of stages in tandem via a plurality of iterations. Each of the stages is arranged to perform a complex key-dependent computation. The stage includes a...
5432848 DES encryption and decryption unit with error checking  
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...
5416841 Cryptography system  
A cryptographic system includes a conventional DES facility for encrypting data using a key of N (=56) bits. The user however need only supply a first key of n bits, which is passed to a key...
5412730 Encrypted data transmission system employing means for randomly altering the encryption keys  
A modem suitable for transmitting encrypted data over voice-grade telephone line. The modem is implemented by the combination of integrated circuit components including a microprocessor, a serial...
5404402 Clock frequency modulation for secure microprocessors  
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...
Matches 201 - 250 out of 344 < 1 2 3 4 5 6 7 >