obtaining random information;

providing the random information to a client computer system;

receiving, from the client computer system, an acoustic fingerprint;

obtaining an encoding of an audio signal;

segmenting the encoding of the audio signal to obtain an ordered set of audio segments, the ordered set of audio segments comprising an audio segment with a size determined based at least in part on a first portion of the random information;

permuting, based at least in part on a second portion of the random information, the ordered set of audio segments to obtain a permuted set of audio segments;

generating, based at least in part on the permuted set of audio segments, a reference acoustic fingerprint;

verifying that the random information was used to generate the received acoustic fingerprint by at least determining that the generated reference acoustic fingerprint matches the received acoustic fingerprint; and

providing, to the client computer system, authorization to access a service based on the verifying that the random information was used to generate the received acoustic fingerprint.