Proposal: Secure Bookmarks

I am tired to not having bookmarks on some of my machines; because I do not want the obvious persistent indicators of what sites I visit frequently enough to warrant a bookmark.

I also want to be able to access these bookmarks across multiple systems and environments.

Thus I would like a portable and secure bookmark storage system.

A centralized bookmark file stored somewhere on the internet, encrypted to be accessible only to authorized users (simple username and password authentication), that can be downloaded and temporarily stored on a local machine, changed, and be able to upload the changes to the central server for access from other machines.

Cost Benefit Analysis
+ Convenient access to bookmarks anywhere
+ Secured bookmarks from people with local access to machines
+ Secure
+ Backup of your bookmarks

- Requires Authentication in a time when people already have enough usernames and passwords to remember
- Having such a file on a central server make a security breach very dangerous as your bookmarks shed much light on your person.

Process
Implement directly into a browser via plug-ins. Support for multiple browsers (FF, Opera, IE) to ensure usability across most systems people will use. Via plug-ins in the browser, point towards the server hosting the bookmarks, authenticate, then download and store temporarily the bookmarks. Save and submit changes to the server before the session is terminated.

Anyone know of a system like I have described that exists, or does anyone want to work on it?

Thoughts or comments on the topic?