design a search algorithm - repost

hi guys , i need an algorithm which i can implement for searching. the question is: an item has thousands of urls and keywords. (say, item = url + keywords) now, when i want to look for a particular item, i have to do a full text search and retrieve the item. the problem is when the no. of items are increasing, what is want is: kindof an encryption algorithm.(not sure if this is appropriate). when the user searches for something, say for 'X' keyword, i dont want to lookup the DB / do a full text search. i want the results to be stored in the 'X' keyword itself. ; so, X theoritically holds the results (or atleast the top 10, 20 of them). so, X is encrypted key and this needs to be decrypted at the client. feel free to pm me , if you have the right skills and caliber no budget constraints... thanks tom