Transport Layer Security (TLS) Resumption Indication Extension
When a TLS session is resumed via an abbreviated handshake, the knowledge of the master secret is used to implicitly mutually authenticate the two peers. However, an attacker can synchronize two different TLS sessions, so that they share the same master secret, breaking the resumption authentication property. This specification defines a TLS extension that cryptographically binds the resumption abbreviated handshake with its original session, thus preventing this attack.