Microsoft Point-to-Point Encryption (MPPE) encrypts data in Point-to-Point Protocol (PPP)-based dial-up connections or

Point-to-Point Tunneling Protocol The Point-to-Point Tunneling Protocol (PPTP) is an obsolete method for implementing virtual private networks. PPTP has many well known security issues. PPTP uses a TCP control channel and a Generic Routing Encapsulation tunnel to encapsulate PP ...

(PPTP) virtual private network (VPN) connections. 128-bit key (strong), 56-bit key, and 40-bit key (standard) MPPE encryption schemes are supported. MPPE provides data security for the PPTP connection that is between the

VPN A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The be ...

client and the VPN server. MPPE alone does not compress or expand data, but the protocol is often used in conjunction with

Microsoft Point-to-Point Compression Microsoft Point-to-Point Compression (MPPC; described in RFC 2118) is a streaming data compression algorithm based on an implementation of Lempel–Ziv using a sliding window buffer. According to Hifn's IP statement, MPPC was patent-encumbered (las ...

which compresses data across PPP or

links. Negotiation of MPPE happens within the Compression Control Protocol (CCP), a subprotocol of PPP. This can lead to incorrect belief that it is a compression protocol. RFC 3078, which defines this protocol, defines

RC4 In cryptography, RC4 (Rivest Cipher 4, also known as ARC4 or ARCFOUR, meaning Alleged RC4, see below) is a stream cipher. While it is remarkable for its simplicity and speed in software, multiple vulnerabilities have been discovered in RC4, ren ...

with either 40-bit or 128-bit key lengths as the only encryption options with this protocol.

External links

* (the protocol), (deriving initial session keys)
MPPE, Microsoft Point-To-Point Encryption Protocol
{{VPN Broken cryptography algorithms Cryptographic protocols Internet protocols Microsoft Windows security technology