XML Trust Services - XKMS:

The XML Key Management Specification (XKMS) initiative was jointly developed by VeriSign, Microsoft and WebMethods as an open standard to simplify the securing of XML-based Internet transactions using PKI and digital certificates. The ability to secure all Web Services communications and transactions is critical for the success of Web Services in the enterprise.

With XKMS, developers can integrate authentication, digital signature, and encryption services, such as certificate processing and revocation status checking, into applications in a matter of hours - without the constraints and complications associated with proprietary PKI software toolkits.

Features and Benefits:

1. Easy to develop
The XKMS specification allows developers to rapidly implement trust features, incorporating cryptographic support for XML digital signatures and XML encryption using standard XML toolkits. The developer-friendly syntax used in XKMS eliminates the necessity for PKI toolkits and proprietary plug-ins.

2. Quick to deploy
XKMS moves the complexity associated with PKI deployment to the server side components. Developers can now focus on their core competency of developing applications rather than the complexities surrounding a PKI deployment.

3. Open Standards
The XKMS specification has been submitted to the World Wide Web Consortium (W3C) as an open standard for distribution and registration of keys. The common XML vocabulary used to describe authentication, authorization, and profile information in XML documents makes XKMS services completely platform, vendor, and transport-protocol independent.

4. Future-proof
By restricting the impact of future PKI developments and advancements to the server-side components, XKMS protects developers and applications from becoming incompatible with the latest developments in PKI.

source: http://www.verisign.com/developer/xml/xkms.html