System, device, and method of secure utilization of fingerprints for user authentication. A method includes: capturing a fingerprint that a particular user provides to an electronic device; generating a raw fingerprint signature that corresponds to bodily features of the fingerprint of the particular user; monitoring user interactions of the particular user, during the capturing of the raw fingerprint, via one or more input units of the electronic device; extracting from the monitored user interactions a user-specific characteristic that is user-specific to the interactions of the particular user; generating a user-specific reference fused data-item, by utilizing both: (I) the raw fingerprint signature that was generated, and (II) the user-specific characteristic that was extracted; subsequently, utilizing the reference fused data-item as a reference for user-authentication.