Continuing with that idea, presenting URLCrypt

2008-02-22 14:12:28 by mcfarland in , (1 comment) permalink

Making LCE gave me an idea. If you use the contents of some URL as the encryption key of a message, then you can essentially make a “this message will self-destruct in five minutes” kind of thing. Meet URLCrypt. What you do is, plug in some plaintext and some URL that a) you have some control over or b) you know will have changed content after some not-too-short amount of time. Encode, grab the result, and send it off. The URL it was encrypted with is encoded along with the message. Your recipient then can then use URLCrypt to decode the message (without knowing the URL it was encoded with). Provided that the URL is still providing the same content, the message will be decrypted fine. If not, gibberish will result. You could use Is It Friday to make messages that are only decryptable on Friday. Neat eh? It wouldn’t take much to make a Web page that would take a token in the query string and serve a decryption key a fixed number of times, or until a certain time, or under any kind of conditions you might want.

© 2008 Rod McFarland because I am so damned clever. Unless, you know, there’s prior art.

Here’s a sample:

[BEGIN URLCRYPT decode at lce.xamai.ca/urlcrypt.php]

OMSDTPXJ2didIM3c3ZABuayACAHUjCgVxRiUvVQB
TRiDd7XAkYCTM0TVgg2LSRCLg0TZnpVWjRUUxaiX
FB1LEhjQDFBUapiXA51cZN3YukWYO2WY49SYBMmL
pFWbsEGev8iO3CHd0hGQL5FQCZmWmGjKAZGU/3yM
pcDIoHmN2E1WyNGRT0SW+JVFKEWR7HVESxSWgriE
2IyFQNCUsUyIVHSYtkCLBPkFwkFXUeRB

[END URLCRYPT]