WP Hashed IDs

This plugin adds a new permalink tag %hashed_id% which represents the encrypted
version of your post ID.
Uses hashids library (see http://www.hashids.org/php/).

With this plugin you can change your permalink structure into something like

/%hashed_id%/ 

to obtain links like

http://www.example.com/B7j1rPk8

or into something like

/%year%/%monthnum%/%hashed_id%/

to obtain URLs like

http://www.example.com/2012/10/B7j1rPk8

or

/%hashed_id%/%postname%/

to obtain

http://www.example.com/B7j1rPk8/my-slug

This plugin is useful when you want to obfuscate the number of posts or simply
if you want an unusual and concise url schema. This is also useful if you want to have
short URLs without using a third-party service.