do Authentication Header(AH provides support for data integrity authentication of IP packets end system/router can authenticate user/app prevents address spoofing /replay attacks by tracking sequence numbers based on use of a mac HMAC-MD5-96 or HMAC-SHA-1-96 parties must share a secret key 復大软件学院11 Authentication Header (AH) • provides support for data integrity & authentication of IP packets – end system/router can authenticate user/app – prevents address spoofing / replay attacks by tracking sequence numbers • based on use of a MAC – HMAC-MD5-96 or HMAC-SHA-1-96 • parties must share a secret key