Hi samdev,
The available encryption algorithms to use with Office depend on the algorithms that can be accessed through the APIs in the Windows operating system. Office 2010, in addition to maintaining support for Cryptography API (CryptoAPI), also includes support for CNG (CryptoAPI: Next Generation), which was first made available in the 2007 Microsoft Office system with Service Pack 2 (SP2). See:
http://technet.microsoft.com/en-us/l.../cc179125.aspx