Abstract
Skype is a secure internet telephonic application which establishes connection between its clients through a peer-to-peer architecture. The connection between Skype client to its server and other clients uses an encrypted channel that uses Transport layer Security (TLS) protocol. At the same time, connection between Skype client and Public Switch telephone Network (PSTN) gateway is accomplished through unencrypted digital channel using Voice over Internet Protocol (VoIP). The encrypted channels in the Skype communication make forensic analysis frameworks to work badly in decrypting the traffic and procuring critical forensic details of the network stream against intruders and cyber criminals. Furthermore, policy violations and unbound usage of Skype VoIP communication over PSTN users waste the network bandwidth. Here we propose a sophisticated Skype forensic framework that collects forensic information by decrypting the Skype client-server communication along with recreating voice content in the Skype to PSTN VoIP communication. We also propose an efficient packet reconstruction algorithm powered by time stamping technique for regenerating malicious content from payloads of the Skype network stream followed by supporting prosecution of policy violators and cyber criminals in the court of law.