| 6025785 |
Multiple code formats in a single garage door opener including at least one fixed code format and at least one rolling code format |
| Feb-15-2000 |
A barrier movement actuating receiver learns and responds to fixed code type access codes and rolling code type access code wherein the actuating receiver includes a programmer for programming the actuating... |
| 5978481 |
Modem compatible method and apparatus for encrypting data that is transparent to software applications |
| Nov-2-1999 |
A method and apparatus for transmitting encoded data from one computer system to another using an AT command set compatible communication device is described. Data being sent from a communications application... |
| 5963646 |
Secure deterministic encryption key generator system and method |
| Oct-5-1999 |
An encryption key generator is disclosed which is highly resistant to cryptographic analysis or brute force attacks, and which accommodates the destruction of an encryption key after each use by providing... |
| 5933501 |
`Virtual` encryption scheme combining different encryption operators into compound-encryption mechanism |
| Aug-3-1999 |
A `virtual` encryption scheme combines selected ones of plurality of different encryption operators stored in an encryption operator database into a compound sequence of encryption operators. Data to be... |
| 5835597 |
Software-efficient pseudorandom function and the use thereof for decryption |
| Nov-10-1998 |
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 encryption key... |
| 5809147 |
Device for cryptographically processing data packets and method of generating cryptographic processing data |
| Sep-15-1998 |
A device for encrypting or decrypting data packets. The device includes two cryptographic elements. The first cryptographic element generates processing data, based on a first starting value, for use in... |
| 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... |
| 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... |
| 5751810 |
Bit agitator |
| May-12-1998 |
A 6-digit decimal input value A and a previously prepared 6-digit decimal extension fixed value L are substituted in an extension function f, thereby extending the input value A to a 12-digit decimal value... |
| 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... |
| 5724427 |
Method and apparatus for autokey rotor encryption |
| Mar-3-1998 |
A method an apparatus for block or stream encrypting text uses an autokeyed rotational state vector to encrypt plain text to yield cipher text. The text is stored as a block in a buffer of an arbitrary... |
| 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... |
| 5675653 |
Method and apparatus for digital encryption |
| Oct-7-1997 |
The present invention is a real time digital encryption system which may be implemented in either hardware or software. The encryption system uses keys and an algorithm in which the encryption is determined... |
| 5675652 |
Computer readable device implementing a software-efficient pseudorandom function encryption |
| Oct-7-1997 |
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 encryption key... |
| 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... |
| 5659618 |
Multi-size cryptographic key system |
| Aug-19-1997 |
A system is employed for providing two different levels of protection for cryptographic devices transmitting digital information. The system is independent of the cryptographic algorithm used and works... |
| 5640455 |
Secret-key enciphering method and arrangement therefor capable of preventing unfair acquirement of information |
| Jun-17-1997 |
ELT transformation circuits 101.sub.1 to 101.sub.m are preliminarily supplied with ELT transformation parameters a.sub.i, b.sub.i, and p.sub.i (i=1, 2, . . . , m). When a plaintext of n bits long is supplied... |
| 5619576 |
Variable-key cryptography system |
| Apr-8-1997 |
Binary data is encrypted or decrypted using a final key. The final key is formed by manipulating one or more user keys, a base key and a block of data, and combining the manipulated keys and data using... |
| 5613005 |
Cipher communication method and device |
| Mar-18-1997 |
Self-synchronizing encryption/decoding circuits are provided with a plurality of irreducible polynomials. An irreducible polynomial to be used in encryption between sending and receiving stations is selected... |
| 5604807 |
System and scheme of cipher communication |
| Feb-18-1997 |
A cipher communication system and scheme capable of realizing the cipher communication without affecting the already existing application programs and hardware, and establishing a synchronization at the... |
| 5602917 |
Method for secure session key generation |
| Feb-11-1997 |
A symmetric procedure avoids the problems with prior art systems using modifiers with master keys and generates a secure session key from a secret master key and an additional pair of randomly selected... |
| 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... |
| 5500898 |
Scramble communication system multiplexing/demultiplexing scramble generation polynomial |
| Mar-19-1996 |
A scramble communication system comprises a station and a plurality of terminals connected to the station. The respective terminals are previously provided with specific scramble generation polynomials... |
| 5479513 |
Fast and secure encryption-decryption method based on chaotic dynamics |
| Dec-26-1995 |
A method and system for the secure encryption of information. The method comprises the steps of dividing a message of length L into its character components; generating m chaotic iterates from m independent... |
| 5425103 |
Variable-key cryptography system |
| Jun-13-1995 |
Binary data is encrypted or decrypted using a final key. The final key is formed by manipulating one or more user keys and a base key, and combining the manipulated keys using an exclusive-OR operation.... |
| 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... |
| 5253296 |
System for resisting interception of information |
| Oct-12-1993 |
A time segment scrambling information encoding and decoding system wherein a multiplicity of scrambling algorithms are stored in a memory such as a ROM for use during transmission via a chosen medium and... |
| 5253294 |
Secure transmission system |
| Oct-12-1993 |
In a secure digital transmission system that may utilize the Data Encryption Standard, the message signal is encrypted according to a predetermined algorithm and a key. The key is selected from a library... |
| 5214704 |
Nonlinear dynamic substitution devices and methods for block substitutions |
| May-25-1993 |
Methods and apparatus for nonlinearizing modulo 2 addition based encryption by block substitution techniques which allows use of the substitution scheme with relatively simple hardware and yet makes cryptanalysis... |
| 5204901 |
Public key cryptographic mechanism |
| Apr-20-1993 |
A public key cryptographic mechanism provides a measurable degree of minimum security, in an ensemble sense, for two Parties, A and B, to establish a commonly held private cryptographic keying variable... |
| 5170431 |
Electronic bolt lock with enhanced security features |
| Dec-8-1992 |
A high security bolt lock is described having the ability to reencrypt the combination code for the lock each time a key is used and thus partially defeat the use of an unauthorized key. The lock may be... |
| 5148480 |
Decoder |
| Sep-15-1992 |
A decoder having a plurality of outputs (R.sub.0 -Rn) each associated with a particular output valve is arranged to add together two binary numbers (A, B) and to select one of the outputs in dependence... |
| 5068895 |
Encryption and decryption methods using bit-length preservation decryptor |
| Nov-26-1991 |
An encrypting method for producing a code which cannot be deciphered by an eavesdropper. The encrypting method does not require the bit length of input information to be increased when the information... |
| 5054067 |
Block-cipher cryptographic device based upon a pseudorandom nonlinear sequence generator |
| Oct-1-1991 |
A block-cipher cryptographic device that processes plaintext/encrypted input data with a key signal to provide encrypted/decrypoted output data. Such device includes a shift register for receiving input... |
| 5008935 |
Efficient method for encrypting superblocks of data |
| Apr-16-1991 |
This invention relates to an arrangement for encrypting data for storage in a computer and/or for transmission to another data processing system. The plain text data is divided into buffers and the buffers... |
| 4984271 |
Cipher system with closed cipher procedure |
| Jan-8-1991 |
A cipher system in a computer network having a host computer and terminal equipments connected by communication lines. A terminal equipment cipher process program memory area is provided in a volatile... |
| 4982429 |
Encipher method and decipher method |
| Jan-1-1991 |
There are provided an encipher method of enciphering message data made by a microcomputer or the like at a high speed by using encipher keys which have previously been stored in a smart card or the like... |
| 4972473 |
Data communication method and apparatus using neural-networks |
| Nov-20-1990 |
A data communication apparatus comprises: means for dividing data to be transmitted into a plurality of blocks and extracting the data from each block; a first multi-layered neural network of three or... |
| 4890324 |
Enciphering/deciphering method and arrangement for performing the method |
| Dec-26-1989 |
A key stream is generated, and successive keys and instruction words are derived from it. A character is enciphered with a derived key by an enciphering operation determined by the instruction word. A... |
| 4724541 |
Data-dependent binary encoder/decoder |
| Feb-9-1988 |
Apparatus for the secure transmission of digital data signals is disclosed in which fixed logic gates and a variable bank of logic gates are used in an encoding circuit to scramble the digital data signals... |
| 4663500 |
Cryptographic system |
| May-5-1987 |
A cryptographic system comprises a modulo-2 adder having a first input receptive of a sequence of binary digits to be scrambled and a second input receptive of a sequence of scrambling binary digits for... |
| 4578532 |
Method and apparatus for code transmission |
| Mar-25-1986 |
A transmission code required for decoding an encoded transmission of messages between a transmitting station and a receiving station is first transmitted from one station to the other. Previously identified... |
| 4503287 |
Two-tiered communication security employing asymmetric session keys |
| Mar-5-1985 |
Communications security between a host computer and another remote computer or terminal is ensured by a means of a two-tiered cryptographic communications security device and procedure. A master key is... |
| 4484025 |
System for enciphering and deciphering data |
| Nov-20-1984 |
A system and method for transmitting enciphered data between first and second terminals over a data transmission channel. The system comprises a transmitter located at the first terminal, a receiver located... |
| 4302628 |
Analog signal encrypting and decrypting system |
| Nov-24-1981 |
An encrypting and decrypting system employing analog signals in which delay lines are employed in both the encrypter and decrypter so that the initial analog signal which is received may be switched by... |
| 4152545 |
Pulse position modulation secret communication system |
| May-1-1979 |
This invention relates to method and apparatus in accordance with which a PPM signal can be encrypted with minimum complexity, involving converting the PPM signal to an encrypted PCM signal, and converting... |
| 4079188 |
Multi-mode digital enciphering system |
| Mar-14-1978 |
The specification discloses an electronic digital enciphering system which is selectively operable in a plurality of different modes. The system may be operated in an off-line mode for preparing enciphered... |
| 4078152 |
Block-cipher cryptographic system with chaining |
| Mar-7-1978 |
A Block-Cipher Cryptographic System utilizing a unique user supplied key to control the cryptographic function and including means for modifying an input data block prior to performing a key-controlled... |
