Abstract: A wireless data communication apparatus having a tamper resistant hardware package which includes a reconfigurable logic device which can be reconfigured in accordance with downloaded program, and a security check device for checking a software program. The encrypted bitfile 551 is decrypted using the terminal secret key 552 (S501). Next, the digital signature is decrypted using the government public key 553. Using hash function, the decrypted bitfile hash or fingerprint is calculated (S503), and if the two match (S504) then the software is legitimate and has not been modified since it was approved (S505).

Abstract: Key encryption key data KEK used for communication between a key management device 3 and receiving apparatuses 4—1 to 4_N is acquired based on a tree divided into two horizontal layers A0 and A1. In this case, the LSD method is employed as a revocation method of each section 31[0] belonging to the horizontal layer A0. Further, the CST method is employed as the revocation method of each section 31[1] belonging to the horizontal layer A1.

Abstract: This invention provides a method and an apparatus for executing improved Boolean matrices based encryption and decryption. In a data communication system, a server generates a series of encrypted data message blocks C1, C2, . . , Cm from plain data blocks P1, P2, . . . , Pm, by computing Ci=K(Pi+K*iVT)Ki. A client receives the encrypted data and generates a series of plain data message blocks P1, P2, . . . , Pn; by computing Pi=K−1CiK*i+K*iVT.

Abstract: This invention provides a method for executing an improved Boolean matrices based encryption, and a data communication system. In a data communication system, a server generates a series of encrypted data message blocks C1, C2, . . . , Cn from plain data blocks P1, P2, . . . , Pn, by computing Ci=K(Pi+KVKi)Kn+i+KVKi. A client receives the encrypted data and generates a series of plain data message blocks P1, P2, . . . , Pn; by computing Pi=K−1(Ci+KVKi)K−(n+i)+KVKi.

Abstract: A wireless data communication apparatus having a tamper resistant hardware package which includes a reconfigurable logic device which can be reconfigured in accordance with downloaded program, and a security check device for checking a software program. The encrypted bitfile 551 is decrypted using the terminal secret key 552 (S501). Next, the digital signature is decrypted using the government public key 553. Using hash function, the decrypted bitfile hash or fingerprint is calculated (S503), and if the two match (S504) then the software is legitimate and has not been modified since it was approved (S505).