A method for authenticating an accessing user for accessing secure data from a first data provider using an authentication system associated with a second data provider, the first data provider being different from the second data provider, the method comprising: receiving, by the authentication system of the second data provider, user credentials and authentication information associated with an enrolling user, the received user credentials including payment card information usable for processing payment card transactions, the received user credentials also useable to access the first data provider; identifying, by the authentication system, an authentication profile associated with the enrolling user, the authentication profile previously stored at the authentication system; linking, by the authentication system, the received user credentials and the authentication information to the authentication profile; storing the received user credentials and authentication information in the authentication profile, wherein the authentication profile is useable by the second data provider for authenticating payment card transactions; receiving, by the authentication system from the first data provider, payment card information associated with the accessing user in response to the accessing user attempting to access secure data stored in the first data provider; comparing the accessing user payment card information received from the first data provider with the user credentials in the stored authentication profile for the enrolling user; transmitting, in response to the comparison, a challenge message based on the stored authentication profile to a user device associated with the accessing user, the challenge message prompting the user device for authentication information, the user device separate from the first data provider and the second data provider; receiving a challenge response from the user device, the challenge response including collected authentication information; authenticating, by the authentication system, the accessing user based on the authentication profile for the enrolling user and the collected authentication information in the challenge response to determine that the accessing user is the enrolling user; and notifying, by the authentication system, the first data provider that the accessing user is authenticated, wherein the first data provider permits the accessing user to access the secure data in response to the accessing user being authenticated. receiving, by the authentication system of the second data provider, user credentials and authentication information associated with an enrolling user, the received user credentials including payment card information usable for processing payment card transactions, the received user credentials also useable to access the first data provider; identifying, by the authentication system, an authentication profile associated with the enrolling user, the authentication profile previously stored at the authentication system; linking, by the authentication system, the received user credentials and the authentication information to the authentication profile; storing the received user credentials and authentication information in the authentication profile, wherein the authentication profile is useable by the second data provider for authenticating payment card transactions; receiving, by the authentication system from the first data provider, payment card information associated with the accessing user in response to the accessing user attempting to access secure data stored in the first data provider; comparing the accessing user payment card information received from the first data provider with the user credentials in the stored authentication profile for the enrolling user; transmitting, in response to the comparison, a challenge message based on the stored authentication profile to a user device associated with the accessing user, the challenge message prompting the user device for authentication information, the user device separate from the first data provider and the second data provider; receiving a challenge response from the user device, the challenge response including collected authentication information; authenticating, by the authentication system, the accessing user based on the authentication profile for the enrolling user and the collected authentication information in the challenge response to determine that the accessing user is the enrolling user; and notifying, by the authentication system, the first data provider that the accessing user is authenticated, wherein the first data provider permits the accessing user to access the secure data in response to the accessing user being authenticated.