1. Introduction

This document defines a way to resume a Transport Layer Security (TLS) session without requiring session-specific state at the TLS server. This mechanism may be used with any TLS ciphersuite. This document applies to both TLS 1.0 defined in [RFC2246], and TLS 1.1 defined in [RFC4346]. The mechanism makes use of TLS extensions defined in [RFC4366] and defines a new TLS message type.

This mechanism is useful in the following situations:

1. servers that handle a large number of transactions from different users

2. servers that desire to cache sessions for a long time

3. ability to load balance requests across servers

4. embedded servers with little memory

This document obsoletes RFC 4507 [RFC4507] to correct an error in the encoding that caused the specification to differ from deployed implementations. At the time of this writing, there are no known implementations that follow the encoding specified in RFC 4507. This update to RFC 4507 aligns the document with currently deployed implementations. More details of the change are given in Appendix A.