decoding/decrypting the website URL

I have seen that some 开发者_运维知识库website uses the passed parameters in encrypted/encoded format. is it possible to decode/decrypt the url to plain text?

yes you can encode and decode the url querystring data.

use

Server.UrlDecode()  - to decode data
and 
Server.URLEncode()  - to encode data 

for encryption

Query string encryption for ASP.NET

There is a difference between encryption and encoding. if the URL parameters are encrypted, only that party can decrypt who knows which algorithm has been used in encryption and also know the keys. On the other hand, encoding is mostly used to safely transmit the URL, so it can be decoded easily.

Yes. If you have the decryption key.

These URLs are usually generated on the server and include encrypted information. It's a mechanism for maintaining state between requests to the server. As it's only the site server that has the encryption key there's no way for you to decrypt it.