D4.3 Tool Support for Evolution-Aware Security Checks and Monitor Generation

The composition of processes is in general not secrecy pre-serving under the Dolev-Yao attacker model. In this paper, we describean algorithmic decision procedure which determines whether the com-position of secrecy preserving processes is still secrecy preserving. As acase-study we consider a variant of the TLS protocol where, even thoughthe client and server considered separately would be viewed as preserv-ing the secrecy of the data to be communicated, its composition to thecomplete protocol does not preserve that secrecy. We also show resultson tool support that allows one to validate the efficiency of our algorithmfor multiple compositions.