Traffic Analysis Attack
A type of attack against Internet encryption. Traffic Analysis can be used to determine what type of information is being communicated (such as chat, email, Web page requests), even if the data itself is scrambled, or encrypted. This attack would be most effective against encrypted proxies.
Traffic Analysis can be defeated through the use of "Dummy Traffic," or sending random data in addition to normal communications. This can be inconvient, taking more bandwidth and processing power and is therefore usually an optional feature of a secure connection. IIP does this.