The BizTalk Adapter for Web Services Enhancements (WSE) 2.0 integrates secure Web services with BizTalk Server 2004. The Adapter for WSE is implemented using the WSE 2.0 framework for Microsoft .NET, and supports WS-Security, WS-Trust, WS-SecureConversation, WS-SecurityPolicy, and WS-Policy. The Adapter for WSE can be used for securely calling Web services and publishing BizTalk orchestrations as Web services.

Get it here: http://www.microsoft.com/downloads/details.aspx?FamilyId=BA643360-E9DC-4FC5-8D60-8E6C5ECA7861&displaylang=en