SNMPv3 provides integrity, authenticity, data privacy, and access control for SNMP messages exchanged between an SNMP manager and the managed SNMP agents. Unlike the community-based administrative model of SNMPv1 and V2C, SNMPv3 unambiguously identifies the source and destination of each SNMP message. And instead of using community names to establish trust between SNMP managers and SNMP agents, SNMPv3 uses the following security-related services to establish trust:
The source includes information in each sent message that identifies the source as authentic, and performs the required functions to ensure message integrity. A typical authentication scheme requires that the source and destination parties share the same authentication key.
Messages are encrypted to achieve privacy. The encryption is done in such a way that only the intended destination can perform the decryption. A typical privacy scheme requires that the source and destination parties share the same privacy key.
Both the source and destination play a part in access control. Each destination may have a distinct access policy for each potential source, which gives an administrator considerable flexibility in setting up an SNMP management system and assigning various levels of authorization to different users.