Cryptographic Services in Silverlight

•System.Security.Cryptography namespace contains classes that enable you to perform symmetric cryptography,
• create hashes and digital signatures, and provide random number generation

Cryptographic Signatures
•Cryptographic digital signatures use a Hash-based Message Authentication Code (HMAC) to provide data integrity.
•When you sign data with a digital signature, someone else can verify the signature,
• and can prove that the data originated from you
•and was not altered after you signed it