Cryptanalysis of Microsoft's PPTP Authentication Extensions (MS-CHAPv2)

The Point-to-Point Tunneling Protocol (PPTP) is used to secure PPP connections over TCP/IP link. In response to [SM98], Microsoft released extensions to the PPTP authentication mechanism (MS-CHAP), called MS-CHAPv2. We present an overview of the changes in the authentication and encryption-key generation portions of MS-CHAPv2, and assess the improvements and remaining weaknesses in Microsoft’s PPTP implementation.

• Type: Conference
• Year: 1999
• Where: CQRE
• Authors: Bruce Schneier, Mudge, David Wagner
• Keywords: Computer Networks, CQRE 1999, Microsoft’s PPTP Implementation, Point-to-Point Tunneling Protocol, PPTP Authentication Mechanism