SNMPv3 added security to the existing SNMPv2 and SNMPv2c specifications. SNMPv3 added authentication and encryption. SNMPv3 uses MD5 and Secure Hash Algorithm (SHA) to create a message digest for each SNMPv3 protocol message. This allows SNMPv3 to prevent data modification for man in the middle attacks, and masquerade attacks. SNMPv3 Managers and Agents can also use Digital Encryption Standard (DES) to encrypt the messages providing better privacy.