Systems and methods for user identity and transaction authentication are described. A user may be authenticated by a terminal configured to process image data of a two-dimensional code to decode key information, the two-dimensional code comprising a cryptographic binding of user credentials including a low-resolution image of the user's face and optionally user biometric data to database user information stored on a secure server. A hash of the two-dimensional code has several digits in common with the hash of the user information stored on the secure server. Authentication may be carried out by computing and comparing the hash values, comparing the high-resolution image of the user's face fetched from the secure server to the user and to the low resolution image embedded in the two dimensional code. The two-dimensional code may be generated to provide access to a restricted area.