Non-repeatable challenge-response authentication

A method, comprising:

• aggregating user-specific electronic activity across a plurality of domains and electronic communication channels, wherein aggregating further includes classifying the user into one or more classifications based on that user's aggregated user-specific electronic activity, wherein classifying further includes:
• randomly selecting a particular classification;
• identifying a template assigned to that particular classification;
• randomly selecting a challenge-response entry from a plurality of entries in the template;
• and
• augmenting the searching of the aggregated user-specific electronic activity with information identified in the challenge-response entry;
• receiving a challenge-response request from an authentication system for a user;
• generating a non-repeatable challenge-response by searching the aggregated user-specific electronic activity with an identifier for the user in response to receiving the challenge-response request;
• providing the non-repeatable challenge-response to the authentication system;
• obtaining a proposed response provided by the user and sent from the authentication system;
• and
• sending an indication of success or failure to the authentication system based on comparing the proposed response against an expected response, wherein the expected response provided in the non-repeatable challenge-response as a particular response along with other improper responses and providing the user authenticated access to an online system based on the indication.