91色情片

Computer viruses often arrive as attachments to emails sent by automated servers or by PCs infected without the owner鈥檚 knowledge. And a new virus can slip through before you鈥檝e had a chance to update the antivirus software. Lucent Technologies has patented a 鈥渞everse Turing test鈥� that it hopes can plug the loophole (US 2003/204569). Lucent鈥檚 software looks for any suspicious incoming email and replies with an explanatory note and simple question, such as 鈥淲hat day is it today?鈥� A human can easily reply accurately, but an infected machine cannot, allowing the software to isolate suspicious emails.