IPsec (Internet Protocol Security)
A set of protocols developed by the IETF to support secure exchange of packets at the IP layer.
IPsec Algorithms And Keys
The currently used version of IPsec (or more specifically IKE) is version 1, which is specified in RFCs 2401-2412 (plus some more).
Version 2 of IPsec is mainly described by the three following RFCs. Note though, that there are very few products that already implement IPsec version 2.
RFC4301, Security Architecture for the Internet Protocol, S. Kent, K. Seo, December 2005, PROPOSED STANDARD.
RFC4302, IP Authentication Header, S. Kent, December 2005, PROPOSED STANDARD.
RFC4303, IP Encapsulating Security Payload (ESP), S. Kent, December 2005, PROPOSED STANDARD.
The Algorithms to use and their requirements are described in RFC4305: Cryptographic Algorithm Implementation Requirements for Encapsulating Security Payload (ESP) and Authentication Header (AH), D. Eastlake 3rd, December 2005, PROPOSED STANDARD.
You also may use some other Cryptographic Algorithms (have a look at the IANA for some other examples).
If linked with Libcrypt Wireshark provides some advanced features such as Decryption of ESP Payloads and/or Authentication Checking. see ESP_Preferences
Is this true for Win32? UlfLamping