message digest
n.
ComputingA unique numerical value derived from a data stream, typically through a one-way hash function, that can be used to test the integrity of the data stream.
A collection of email messages sent to a distribution list over a period of time and combined into a single email message for distribution.
Notes
A message digest1 can be generated using the MD5, secure hash algorithm (SHA), or other algorithms. If a message digest is calculated on a data stream and compared to an earlier message digest, it is possible to determine if there has been even a minor alteration in the content of the data stream. Message digests are key components of digital signatures.