Aesulate uses AES in counter mode to encrypt RSS and Atom feeds. Most textual fields in the feed are replaced with AES encrypted versions of themselves. A greasemonkey script is provided that will decrypt AES encrypted content when seen.

All encrypted strings are prefixed with a HMAC-SHA1 of the ciphertext. This allows aesulate to check that the ciphertext was generated by a person holding the key. Additionally, providing an incorrect key is detected, rather than decrypting the ciphertext to incorrect plain text.

A possible use for this script: feeding private content into a service such as Google Reader, via a public feed that doesn't need to be protected.

This project is alpha quality. Note that only trusted RSS feeds should be decrypted via the greasemonkey script due to the potential for DOM-based cross-site-scripting. See the README for more details.