Message Digest - Hashing

Form of cryptographic security but different from Encryption

• A message digest is a cryptographic hash function containing a string of digits created by a one-way hashing formula.

• Encryption is a two-step process used to first encrypt and then decrypt a message

• Hashing condenses a message into an irreversible fixed-length value, or hash

• MD5 & SHA-1

• Only used to verify the data. Message cannot be retrieved back.

• Hash is a result of the original message plus a secret key

• md5sum and sha1sum utilities on a Linux or UNIX machine to experiment with hashing

• Also known as Message Digest , Hashing, Checksum.

• Checksums or digital fingerprints at download sites