Message Digest:
Message digests help verify that a message has not been
altered because altering the message would change the
digest.
Electronic Wallet
Software
loaded onto a personal computer containing a customer's
payment card
information, digital certificates and cryptographic keys.
Digital Signature:
A code that guarantees a sender’s identity. If an unauthorized
person
decrypts it, the digital signature will be altered and the
recipient will
know of the tampering.