I just posted the first release of moinmoin-client-crypt to GitHub. As way of introduction, here’s an excerpt from the readme:
moinmoin-client-crypt provides client-side encryption/decryption of MoinMoin wiki pages (or portions thereof). It adds encrypt/decrypt buttons to the edit screen, providing an easy mechanism to secure all or a portion of the content. Encryption is via Chris Veness’ Javascript AES implementation (256 bit key, CTR mode).
Installation involves dropping a couple JavaScript files into the appropriate MoinMoin directory and tweaking the theme init file to reference them. Full functionality with modern and classic themes, perhaps slightly degraded on others. It shouldn’t take much tweaking to adapt to other themes; patches and bug reports are welcome!
The client-side JavaScript approach provides some security if the server were to be seized: the AES ciphertext should be extremely difficult to crack. Also, once the browser is closed on the client side, there should be no trace left of the plaintext. However, if the server were compromised it would be easy to replace moinmoin-client-crypt with a trojan horse if a malicious person were to gain control of the client, they could easily install e.g. a keylogger you have to trust your client machine, your browser, your connection to the server, and the integrity of the server, as explained here by Nate Lawson. The need for client-side security should be obvious; the server and connection must be trusted not to send/inject a modified version of the script.