Hiding URL of page in Asp.Net

Hiding URL of page in Asp.Net

Suppose u have main pages default.aspx. and u are using query string to tranfer sensitive data.  And u want to hide it.Now ur next url are like 
Localhost:1528//Abc/product.asp?a=100;
Localhost:1528//Abc/product.asp?a=50;
Localhost:1528//Abc/product.asp?a=70;
Now u want instead of showing these url a coomon url as
Localhost:1528//Abc/allproduct.aspx
For this  go to allproduct.aspx from default.aspx and in 
Page_load method use Serve.Transfer(Localhost:1528//Abc/product.asp?a=50);
Now ur getting the information from  this page Localhost:1528//Abc/product.asp?a=50 but ur url will showing as Localhost:1528//Abc/allproduct.aspx
So when ur tranfering from default.aspx to allprpduct.aspx  just transfer the appropriate url eg Localhost:1528//Abc/ product.asp?a=50