Age verification

A system for verifying an age of a user, comprising:

• a client device comprising a memory and at least one processor coupled to the memory and configured to:
• receive an image of a face of the user;
• generate a plurality of output values based on the image using a plurality of machine learning models, each machine learning model trained to output a confidence value regarding an attribute related to verifying the age of the user;
• generate a feature tensor by inputting the plurality of output values into a first sub-model of a final machine learning model;
• generate a one-time age token by encrypting a payload comprising the feature tensor;
• and
• provide the one-time age token to the user;
• and
• a server device comprising a second memory and a second at least one processor coupled to the second memory and configured to:
• receive the one-time age token;
• and
• verify the one-time age token and derive an estimated age by inputting the feature tensor into a second sub-model of the final machine learning model, wherein the one-time age token remains valid for a certain amount of time after being generated.