Is Cookies hashed by default

[Tommy]

If I stored some data in a cookie, does ASP.NET hash the values in
cookies by default to prevent the data from being tempered?

If ASP.NET does hash cookies by default, what algorithm does it use?
Also, can I enable/disable this feature through the Web.Config, and
can I use a different algorithm.

If ASP.NET does not hash cookies by default, how can I make ASP.NET
hash the cookie. Will it be some settings in Web.Config, or will it be
custom code.

Thanks in advance.