TKIP - Definition and Overview

In computing, TKIP is a security protocol defined in IEEE 802.11i specifications for WiFi networks to replace WEP. TKIP was designed to replace WEP without replacing legacy hardware. This was necessary because the breaking of WEP left WiFi networks without viable link-layer security. The solution to this problem could not wait on the replacement of deployed hardware. For this reason, TKIP (pronounced "tee-kip"), like WEP, uses a key scheme based on RC4, but unlike WEP it encrypts every data packet sent with its own unique encryption key.

It also hashes the initialization vector (IV) values that are sent as plaintext in the current release of WEP. This means that IVs are now encrypted and are not as easy to sniff out of the air (addressing one of WEP's largest security weaknesses).

TKIP provides per-packet key mixing, a message integrity check and a re-keying mechanism, thus addressing other security issues with WEP. This increases the complexity of decoding the keys by reducing the amount of data available to the cracker, that has been encrypted using a particular key.

References

Jon Edney and William A. Arbaugh, Real 802.11 Security: Wi-Fi Protected Access and 802.11i, Addison Wesley, 2003

External links

• Temporal Key Integrity Protocol 1 (http://www.informit.com/guides/content.asp?g=security&seqNum=58)
• Temporal Key Integrity Protocol 2 (http://www.mpirical.com/companion/mpirical_companion.html)
• 3 (http://www.mpirical.com/companion/IP/TKIP_-_Temporal_Key_Integrity_Protocol.htm)