andreyk

The plugin increases security of a site in case it has no SSL certificate, 
useful for owners of small sites who want to secure their passwords and 
other posted data but don’t want to buy SSL certificate for each domain 
and subdomain: it protects from sniffering the most important data such as 
passwords when they are being sent from forms of your site to the server.
When the form served by the plugin is submitted all input data are being 
joined into a string, then this string is being encrypted with AES algorythm 
by disposable key and only encrypred string will be sent.
A browser encrypts the disposable key in javascript by the RSA public key 
and sends it to the server; then the server decrypts it with the RSA private 
key and then use it to decrypt the posted data with AES.
Translations included: Ukrainian, Russian, German and Brazilian Portuguese.
I just adapted usage in WordPress the jCryption jQuery plugin, v. 3.1.0. 
Please check www.jcryption.org to learn how jCryption works.

WP jCryption Security

Prevents forms data against sniffing network traffic through encryption provided by jCryption javascript library.

marcusds

Encrypts WordPress blog posts and pages so that even with access to the WordPress database your posts will still be private and secure. This plugin is in ALPHA! Be incredibly careful in your use of it. If you want to try this plugin out best to do so on a new install for now, works nicely then at least. For maximum security and the only way you will know 100% your data is safe in transmission is if you use HTTPS as well.

Encrypted Blog

The ultimate in WordPress privacy and security. Encrypts WordPress blog posts and pages so that even with access to the WordPress database your posts  …

WP jCryption Security vs Encrypted Blog