XKMS, now a W3C-recommended standard, enables building PKI-like services for Web service client requests. It allows the reuse of the existing PKI while providing standards-based access to public key registration and validation.
XKMS consists of XKRSS and XKISS, which provide standard protocols for key registration and identification. XKMS has been designed to work hand-in-hand with other Web service security standards like XML encryption and XML digital signatures. An XKMS-compatible service provider can interpret the XML key information, thus enabling Web service clients to make use of third-party services for key processing.