초록 ▼

According to a cryptographic communication system which can safely perform cipher conversion processing when cryptographic communication is performed between terminals using different cipher types, when a terminal 10A-1 connected to a LAN-A using a cryptographic algorithm C1 transmits data to a term

According to a cryptographic communication system which can safely perform cipher conversion processing when cryptographic communication is performed between terminals using different cipher types, when a terminal 10A-1 connected to a LAN-A using a cryptographic algorithm C1 transmits data to a terminal 10B-1 connected to a LAN-B using a cryptographic algorithm C2, the terminal 10A-1 generates two meaningless data items from the data to be transmitted, decrypts the two generated data items according to the cryptographic algorithm C1, and then transmits the decrypted data to two cryptographic protocol conversion servers and for dividing the data into two data items. Each of the cryptographic protocol conversion servers decrypts each transmitted data item, the re-encrypts the decrypted data according to the cryptographic algorithm C2, and then transmits the data to the terminal 10B-1. The terminal 10B-1 restores original transmission data on the basis of the two data items transmitted from the respective cryptographic protocol conversion servers.

대표청구항 ▼

[ What is claimed is:] [1.] A cryptographic communication system including at least one of first type terminals using a first cipher type, at least one of second type terminals using a second cipher type different from the first cipher type, and n cryptographic protocol conversion servers (n.gtoreq.

[ What is claimed is:] [1.] A cryptographic communication system including at least one of first type terminals using a first cipher type, at least one of second type terminals using a second cipher type different from the first cipher type, and n cryptographic protocol conversion servers (n.gtoreq.2) using the first and second cipher types, said first type terminals, said second type terminals and said cryptographic protocol conversion servers being connected to one another through at least one of networks; whereinsaid first type terminal includes:dividing means for dividing data to be transmitted to a terminal of said second type terminals into k items of data to be distributed among k cryptographic protocol conversion servers (n.gtoreq.k.gtoreq.2) of said n cryptographic protocol conversion servers on the basis of the data to be transmitted to a terminal of said second type terminals;encryption means for encrypting the k items of data generated by said dividing means according to the first cipher type; andtransmitting means for adding terminal information representing each of said first type terminals and said second type terminals to each of said k items of data encrypted by said encryption means and then transmitting said k items of data encrypted to said k cryptographic protocol conversion servers respectively, via said at least one of networks;each of said k cryptographic protocol conversion servers includes:cipher conversion means for decrypting said one data item of data encrypted according to the first cipher type, which was transmitted from said first type terminals via said at least one of networks, and then re-encrypting the decrypted data item according to the second cipher type; andtransmitting means for transmitting the one data item re-encrypted by said cipher conversion means to said second type terminal which is indicated by the terminal information added to the data; andsaid second type terminal includes:decryption means for decrypting the k items of data transmitted from each of said k cryptographic protocol conversion servers according to the second cipher type; andrestoring means for restoring original data from the k items of data decrypted by said decryption means.