You will need to implement SAML v2.0 for your online service. Secure Assertion Markup Language (SAML) is the international standard from the Organization for the Advancement of Structured Information Standards (OASIS) which ensures secure messaging between your online website and RealMe® services.
For Java and .NET there are a variety of open source libraries and commercial offerings - there are also toolkits for other environments including PHP, Ruby, and Perl. Many enterprise identity and access management products such as OpenAM, Ping, Microsoft ADFS and IBM Tivoli already have built-in support for SAML. We have a list of SAML options that have been used to integrate with RealMe services. Read more about the technical considerations that may apply when selecting a SAML component and deploying RealMe services.
The following sequence diagrams illustrate the typical steps for a user at an agency interacting with RealMe services - the patterns for login service and assertion service are quite similar.