Carnivore, Sniffers, And You
Not too long ago, a small delicatessen down the road from my house closed their doors. This deli specialized in huge, reasonably-priced, meat-filled sandwiches and for that reason was aptly named "Carnivores." Despite sitting just a stone's throw from the Interstate, Carnivores apparently failed to attract a busy enough "network" of customers to stay in business.
Recently the U.S. Federal Bureau of Investigation (FBI) unveiled a new tool in their ongoing fight against crime -- a controversial network sniffer named -- you guessed it -- Carnivore. Not all of the details on Carnivore have been released, but the beast has had some networking professionals and privacy advocates "up in arms" so to speak.
Graphic courtesy Federal Bureau of Investigation
Just like my local restaurant, Carnivore probably intimidates or offends some people just because of its name. Good advertising and "branding" can make or break a business. Also like the restaurant, Carnviore faces some serious competition. Network sniffers are nothing new, and already some alternatives to the secretive Carnivore system have been discussed.
How Carnivore Behaves
|"Electronic surveillance has been extremely effective in securing the conviction of more than 25,600 dangerous felons over the past 13 years" - F.B.I. (formerly posted at www.fbi.gov/programs/carnivore/carnivore.htm)|
The Carnivore system consists of an ordinary personal computer running Microsoft Windows and some proprietary (closed-source) software . Carnivore's primary purpose is to intercept large volumes of electronic mail and other forms of electronic communication passing through a network . This listening process remains passive at all times; it alters no data and prevents no messages from continuing on to their intended destination.
Carnivore can theoretically scan millions of emails per second -- processing as much as six gigabytes (6,000 megabytes) of data every hour according to MSNBC (formerly posted at www.msnbc.com/news/431355.asp). It targets data much more selectively in practice. By scanning the subject lines and headers of incoming or outgoing messages, the system identifies relevant communications among selected individuals as part of a criminal investigation. Data deemed useful can be off-loaded onto removable drives and retrieved through secure dial-up sessions.
"The system is not susceptible to abuse because it requires expertise to install and operate, and such operations are conducted, as required in the court orders, with close cooperation with the ISPs." Source: FBI
The FBI named this system "Carnivore" in reference to its objective of collecting hard ("meaty") data. However, Carnivore captures only the raw bits of information. Messages that users encrypt with readily-available tools like PGP, for example, are not "cracked" by the system. Decoding these messages offline can require serious effort on the part of investigators.