Patent ID: 6842523

Claim:
A cryptographic communication system comprising: an encryption apparatus for encrypting a data body and for transmitting transmission data to a receiver, the transmission data including: an encrypted data body; sender's key recovery data obtained by encrypting recovery information for recovering a key for decrypting the encrypted data body to allow a key recovery agent registered by a sender to decrypt the recovery information; and receiver's key recovery data obtained by encrypting the recovery information for recovering the key for decrypting the encrypted data body to allow the key recovery agent registered by the receiver to decrypt the recovery information; a plurality of the key recovery agents each, when registered by the sender or the receiver, capable of decrypting a sender's or a receiver's key comprised of a plurality of key pieces obtained by dividing the key into pieces, wherein each key recovery agent decrypts and sends back the sender's or the receiver's key recovery data only when a request is made by a party approved by an approver; and an approver apparatus for approving a requester for a key recovery agent registration approval and approving an authorized third party, who requests an approval for decrypting the sender's or the receiver's key recovery data, to decrypt the senders or the receiver's key recovery data.