No authentication – Ideal when you want to quickly present a document to a user and quickly obtain their e-signature

Username & password – The basic level of user authentication and access control

Two-factor authentication – A popular technique is to send a One Time Password (OTP) to the person’s mobile phone via SMS

External Identity Providers– External identity providers use standard protocols such as SAML, OAuth, OpenID and Radius to confirm a user’s identity. Example identity provider authentication mechanisms include Knowledge Base Access (KBA), mobile authentication, corporate Active Directory authentication, social media authentication and Google Authenticator

Locally-held PKI tokens – The user’s signing key is held within a secure tamper-resistant smartcard or USB token. A good number of countries have issued citizen e-IDs containing PKI signing keys built-in that can be used with SigningHub. Corporate PKI smartcards for physical and logical access control can also be used as can the PIV cards used extensively with the US Federal Agency, Defence and financial organisations