Limiting receiver access to secure read-only communications over a network by preventing access to source-formatted plaintext

Abstract

Receiver access to a secure communication is determined by the sender. The sender defines an access parameter, such as number of times a message can be decrypted, expiration time of message, or some contingent event that triggers expiration of a message. A send configuration module defines the encryption method, encryption key length, and the control parameter(s). A key management module serves to implement the send configuration parameters during a communication. Upon receiving a message the receiver module contacts the key management module to request a decryption key. The key management module returns the decryption key or a 'denied' message. Once the message is decrypted at the receiver, the key and the decrypted source are deleted from the receiver computer. The message is displayed in a bit-mapped window.