Scalable , High Speed , Internet Time Synchronization

This memorandum describes extensions to the Network Time Protocol (NTP) version 3, described in RFC 1305 [MIL92], and the Simple Network Time Protocol (SNTP) version 4, described in RFC 2030 [MIL96a], to create a framework for interoperability and coexistence of various cryptographic signature and authentication schemes that have been suggested as enhancements to NTP/SNTP [MIL96b]. Without describing any particular approach to authentication in detail, a framework is hereby established for these schemes and methods to coexist and interoperate on a single network or Internet. NTP v3, as specified in RFC 1305, provides support for a method of symmetric-key authentication. This model requires independent, out-of-band, distribution of cryptographic keys, with the associated risk of compromising those keys during distribution. This process is too costly and too great a security risk for universal application. The NTP protocol extensions described here allow for the creation of certified time from a certified and authenticated time source, for use in portable commercial-grade trust, nonrepudiated logging, cryptographic synchronization, and other critical network management