RFC 2574 USM for SNMPv3 April 1999 2.2. Replay Protection 13 2.2.1. msgAuthoritativeEngineID 13 2.2.2. msgAuthoritativeEngineBoots and msgAuthoritativeEngineTime14 2.2.3. Time Window 15 2.3. Time Synchronization 15 2.4. SNMP Messages Using this Security Model 16 2.5. Services provided by the User-based Security Model 17 2.5.1. Services for Generating an Outgoing SNMP Message 17 2.5.2. Services for Processing an Incoming SNMP Message 19 2.6. Key Localization Algorithm. 21 3. Elements of Procedure 21 3.1. Generating an Outgoing SNMP Message 22 3.2. Processing an Incoming SNMP Message 25 4. Discovery 30 5. Definitions 31 6. HMAC-MD5-96 Authentication Protocol 50 6.1. Mechanisms 50 6.1.1. Digest Authentication Mechanism 50 6.2. Elements of the Digest Authentication Protocol 51 6.2.1. Users 51 6.2.2. msgAuthoritativeEngineID 51 6.2.3. SNMP Messages Using this Authentication Protocol 51 6.2.4. Services provided by the HMAC-MD5-96 Authentication Module52 6.2.4.1. Services for Generating an Outgoing SNMP Message 52 6.2.4.2. Services for Processing an Incoming SNMP Message 53 6.3. Elements of Procedure 53 6.3.1. Processing an Outgoing Message 54 6.3.2. Processing an Incoming Message 54 7. HMAC-SHA-96 Authentication Protocol 55 7.1. Mechanisms 55 7.1.1. Digest Authentication Mechanism 56 7.2. Elements of the HMAC-SHA-96 Authentication Protocol 56 7.2.1. Users 56 7.2.2. msgAuthoritativeEngineID 57 7.2.3. SNMP Messages Using this Authentication Protocol 57 7.2.4. Services provided by the HMAC-SHA-96 Authentication Module57 7.2.4.1. Services for Generating an Outgoing SNMP Message 57 7.2.4.2. Services for Processing an Incoming SNMP Message 58 7.3. Elements of Procedure 59 7.3.1. Processing an Outgoing Message 59 7.3.2. Processing an Incoming Message 60 8. CBC-DES Symmetric Encryption Protocol 61 8.1. Mechanisms 61 8.1.1. Symmetric Encryption Protocol 61 8.1.1.1. DES key and Initialization Vector. 62 8.1.1.2. Data Encryption. 63 8.1.1.3. Data Decryption 63 8.2. Elements of the DES Privacy Protocol 63 Blumenthal & Wijnen Standards Track