From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:
10.4.5 404 Not Found
The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent.
If the server does not wish to make this information available to the client, the status code 403 (Forbidden) can be used instead. The 410 (Gone) status code SHOULD be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable and has no forwarding address.
Ellen Messmer writes: The danger that emerges when the cunning combine virus code and encryption is the topic of this 392-page volume by Adam Young and Moti Yung. The result of blending a virus and cryptographic techniques might be a computer worm that could encrypt the files stored in computers it attacks, rendering access to the information impossible. Or it might be a trojan horse that makes use of digital signatures for optimum control by its maker. The varying possibilities, laid out in the jargon of the crypto geek, is both a wake-up call to corporations and governments, and unfortumately, a textbook for putting cryptovirology into action.
