Sometimes a signed message requires a countersignature. For example, user A may send a signed-data message to user B, expecting B to confirm agreement with the terms contained in the document. User B decodes the message, reads the terms and, if in agreement, countersigns the message. The countersigned message is then sent back to user A. User A now knows, and can prove, that user B agreed to the terms.
The following table lists sections that contain procedure descriptions or C program examples of message countersigning.
|Message Functions||Lists the counter signature functions.|
|Countersigning a Message||Details the process of counter signing a message.|
|Verifying a Countersignature||Details the procedure for verifying a counter signature.|
|Verifying a Signed Message||Details a process for verifying the signature on a signed message.|
|Example C Program: Encoding and Decoding a CounterSigned Message||Sample C program that encodes and decodes a countersigned message.|