Method for authenticating a timepiece comprising measuring acoustic vibrations emitted by said timepiece to obtain an electrical signal indicating magnitude information comprising a variation of a magnitude of the measured acoustic vibrations as a function of time. The electrical signal comprises at least one specific tone associated with the presence of a quartz resonator in the timepiece. Method further comprises performing transform of electrical signal into frequency domain to obtain frequency-domain power spectrum indicating variation of power of electrical signal as function of frequency, processing the frequency-domain power spectrum so as to reveal at least one narrow peak in frequency-domain power spectrum corresponding to the at least one specific tone, and extracting at least one resonance frequency corresponding to said at least one narrow peak. Method further comprises comparing extracted at least one resonance frequency with at least one reference resonance frequency; and determining an authenticity of said timepiece.

A method for authenticating a timepiece including measuring acoustic vibrations emitted by said timepiece to obtain an electrical signal, said electrical signal indicating a variation of a magnitude of said measured acoustic vibrations as a function of time, wherein said electrical signal comprises a plurality of acoustic events associated with mechanical shocks taking place in said timepiece, extracting from said electrical signal or from a representation of said electrical signal in a time, frequency or time-frequency domain at least one of a magnitude information on a magnitude of one of said plurality of acoustic events, time information on said one of said plurality of acoustic events, and a frequency information on a frequency of said one of said plurality of acoustic events, comparing said extracted information with at least one of a reference information, and deriving information on an authenticity of said timepiece based on the comparing.