Electronic
system (106, 109A) for authenticating a user of an
electronic service, said
system preferably comprising at least one
server apparatus, the
system being configured to store (122, 112, 200), for a number of users, a plurality of personal voice-prints (204) each of which being linked with a dedicated visual, audiovisual or audio cue (202), for challenge-response
authentication of the users, wherein the cues are user-selected, user-provided or user-created, pick (116, 200C, 142, 144), upon
receipt of an
authentication request associated with a claim of an identity (160) of an existing user of said number of users, a subset of cues (212) for which there are voiceprints of the existing user stored (112), and provide the cues for representation to the user as a challenge, receive (126, 148, 150) sound data indicative of the voice responses uttered by the user to the represented cues, said voice responses being captured utilizing both air and
throat microphones, determine (114, 152, 154, 156, 158) on the basis of the sound data, the represented cues and voiceprints linked therewith and the existing user, whether the response has been uttered by the existing user of said number of users, wherein the sound data indicative of the voice responses uttered to the represented cues are preferably matched as concatenated against a concatenated voiceprint established based on the voiceprints linked with the represented cues and the existing user, and provided that this seems to be the case, elevate (116, 152, 200D, 218, 216) the
authentication status of the user as the existing user, preferably regarding at least the current communication session. Related method and device (102c) are presented.