Secure authentication

Disclosed embodiments relate to passwordless authentication. Techniques include identifying a request by a user to access an access-restricted target resource, the user operating on a client computing device and the request being associated with a network address for the access-restricted target resource; intercepting the request; generating a unique session identifier for the user; making available the unique session identifier to the user of the client computing device; performing dual-mode, passwordless authentication of the user; confirming, based on the dual-mode, passwordless authentication of the user, the identity of the user and the user's current use of the client computing device; and permitting, based on the confirmation, the user to access the access-restricted target resource.