ReFormat: Automatic Reverse Engineering of Encrypted Messages

Date Added: Jun 2009
Format: PDF

Automatic protocol reverse engineering has recently received significant attention due to its importance to many security applications. However, previous methods are all limited in analyzing only plain-text communications wherein the exchanged messages are not encrypted. In this paper, the authors propose ReFormat, a system that aims at deriving the message format even when the message is encrypted. The approach is based on the observation that an encrypted input message will typically go through two phases: message decryption and normal protocol processing. These two phases can be differentiated because the corresponding instructions are significantly different.