Matches 1 - 19 out of 19
Match Document Document Title
7239709 Data recording/reproducing method, data recording/reproducing system, recording apparatus  
A data recording/reproducing method wherein encrypted digital data obtained by subjecting digital data to first encrypting by using a contents key and encrypted contents key obtained by subjecting...
6587948 Recording apparatus, recording medium, playback apparatus, recording method and playback method  
A recording method and a recording apparatus whereby digital data is recorded onto a disc as run-length limited code used for modulating marks or spaces on the disc and, at the same time, the...
6125186 Encryption communication system using an agent and a storage medium for storing that agent  
An agent is permanently resident in a server as software for the purpose of cryptographic processing. In addition, another agent that is described in mobile code and contains a program for the...
6041411 Method for defining and verifying user access rights to a computer information  
A method for minimizing the potential for unauthorized use of digital information, particularly software programs, digital content and other computer information, by verifying user access rights to...
4972475 Authenticating pseudo-random code and apparatus  
A matrix code generating method generates a first predetermined code in binary form. A second step permutes the first determined code according to a non-linear feedback method described as...
4591704 Data scrambling system and method  
Credit cards to be used with automated systems such as vending machines or the like have various identification and other data encoded on them for use with a particular system for which they are...
4217469 Coding and decoding apparatus for the protection of communication secrecy  
Apparatus for coding and decoding of electrical signals within a pre-established frequency band and useful for providing communication secrecy. A transmission and coding circuit and a reception and...
4125744 Communication system  
In a pulse code modulation system, a source of key signals comprising a source of random pulses, multisection delay device, means for applying said pulses to said multisection delay device,...
3485948 PERFORATED TAPE ACCESSORY APPARATUS FOR A CIPHERING MACHINE  
3479456 SYNCHRONIZING MECHANISM FOR ENCRYPTING TELEGRAPH TRANSMITTER  
3345500 Cyclic code generating means  
3319000 Ciphering device  
3214518 Apparatus for coding and decoding teleprinter messages  
3067299 Combination-code signal-generating apparatus  
3057955 Cryptographic ancillary equipment  
2981794 Teleprinter secrecy system  
2949501 Apparatus for producing punched coding tapes of very long period  
2897268 Cipher telegraph system  
2872514 Random signal generator  
Matches 1 - 19 out of 19