Attacks on re-keying and renegotiation in Key Exchange Protocols Bachelor Thesis

The TLS protocol has been a subject of studies, analyses and verification attempts over the years, but a recently discovered attack against the key renegotiation in the TLS protocol underlined the need to more thoroughly study the key renegotiation phase and focus on aspects not investigated before. We study the key renegotiation phase of the TLS protocol and use formal models for automatic verification and detection of potential security flaws. The models we developed capture the vulnerability that led to the recently discovered attack against TLS. We also investigate the key renegotiation aspects of two other protocols, IKEv2 and SSH2.