hide just one parameter in the URL

I am working with a company who has a old web app running on .net 1.1

We are passing a critical information in the querystring, how can I hide just that parameter, the problem is, it is being sent from several hyperlinks, forms, response.redirects etc... I can't use session either because it will be a huge change in the application, and right now we are not planning implement any major change.

So 开发者_运维技巧my question is, is there a way that I can encrypt/decrypt just that parameter from the querystring, probably at any event that asp page fires?

or maybe there is another of doing it?

Thanks,

This post contains code for an HttpModule which decrypts an entire query string: (encrypt and decrypt query string) and then rewrites the path enabling the pages in application to pull the decrypted params.

You could modify the HttpModule to look for a single parameter and decrypt that.

After decryption you could rebuild the query using the decrypted param along with the rest of the original query and rewrite the path using it.