The present invention relates to a method of processing a transaction sent from a proof entity (1) connected to a verification entity (2);



the proof entity (1) having at least one secret key and a candidate authentication data, the verification entity (2) having the hash value of a reference authentication data;
the method comprising the steps of:
(a) generation by data processing means (11) of the proof entity (1) of:

a signature of the proof entity (1) from said secret key;
a zero-knowledge proof of the fact that the candidate authentication data and the reference authentication data match;


(b) transmission to the verification entity (2) of transaction data comprising at least:

said signature of the proof entity (1);
said zero-knowledge proof;


(c) verification by the data processing means (21) of the verification entity (2) that said signature of the proof entity (1) and the zero-knowledge proof are valid;
(d) processing said transaction.