IGTF Levels of Authentication Assurance

The IGTF Authentication Profiles describe a technology-agnostic assurance level that represent the IGTF consensus on achievable trustworthy authentication seen from both the relying party pooint of view as well as being a feasible level for identity service providers to achieve for a variety of scenarios.
Traditionally assurance levels have been identified on a single scale. In terms of a single linear scale, relying parties have often considered authorities compliant with ASPEN (PKI implementation: SLCS), BIRCH (PKI implementation: MICS), or CEDAR (PKI implementation: Classic Secured) to be similar in terms of assurance level, and authorities compliant with DOGWOOD (PKI implementation: IOTA) to be different. In this document, several aspects are separated and relying parties may find more fine-grained controls.