place to save sensitive data when user move between pages

 Hi all,
There are a list in page A, and when a user click a row on the list, I need to show detailed information in Page B.
Normally we would do it using request query string (e.g. http://www.....?id=007), but this time it's some private data like account number etc,
I am thinking about using session data, so that I can save data into session in Page A, and then get the data in Page B. But I am not sure this is the best approach or not.
Have you got any good suggestions?  : )
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