What is the strongest encryption available in .Net 3.5
.net, encryption
Solution
DES is obsolete. Its 56 bit key basically can be brute forced by a laptop computing power in a matter of hours. The best symmetric key encryption that .Net ships with out of the box is AES 256 (http://msdn.microsoft.com/en-us/library/system.security.cryptography.aescryptoserviceprovider.aspx). A comparison of Blowfish and AES (aka. Rijndael) is beyond the scope of this discussion, but AES is the adopted NIST standard and the way to go for the foreseeable future. See http://en.wikipedia.org/wiki/Advanced_Encryption_Standard for more details.
Problem
I am storing files in S3 and want to encrypt the data to the maximum. I am using ThreeSharp S3 library and it uses DESCryptoServiceProvider to encrypt the data. How strong is DESCryptoServiceProvider compared to other encryption available in .Net? I have also seen services like Mozy.com that use 448-bit Blowfish encryption. I have done some research and found some free libraries that offer Blowfish. But nothing that tells why Blowfish is better than what .Net provides. I need to know what is the strongest encryption possible in .Net 3.5. I would also like any suggestions on other libraries that might not be in .Net that would offer higher encryptions.