This invention overcomes the disadvantages of the prior art by providing a system and method for cryptographic communication that allows for the use of identical random number database structures located on the sending and receiving clients to randomly encode and decode messages based on encoded instructions on how to apply the database to encode and subsequently decode the underlying encoded message data, allowing for a secure and keyless transfer of message data between the sender and the recipient. Illustratively, an encoded message on a sending client with an appended header containing the filename, a unique synchronization block and instruction set with the method and starting point is encoded again to obscure the header. The message is transmitted and received by a receiving client and decoded, first by trial and error on the header portion to reveal the header, and then the remaining message data according to the revealed instruction set.