Sending a message securely on an insecure channel. The message is encoded in the form of a singular matrix, and multiplied with a first non-singular matrix. The resulting first cipher data is sent to a receiver system. Receiver system multiplies the first cipher data with a second non-singular matrix and the resulting second cipher data is sent to the sender system. The sender system multiplies the second cipher data with the inverse of the first non-singular matrix, and the result is sent to the receiver system. The receiver system multiplies the received result with the inverse of the second non-singular matrix to recover the message.