A system for generating a strong private key (K s pri) for a user using a biometric value (K bio) representative of an analogue source, the system comprising: a secure server for storing a secure data vector, the secure data vector comprises user information, a weak public key (K w pub), a strong mapping key (K s map), a strong mapping function and a random number (K rand); a public server for storing an open data vector, the open data vector comprising the user information, an ambiguity resolution vector, a weak mapping key (K w map) and a weak mapping function; a computer terminal for communicating with the public server and the secure server, the computer terminal being arranged for: - generating a biometric value (K bio) using biometric data received by the computer terminal; - generating a weak private key (K w pri) using said biometric value (K bio), the weak mapping key (K w map) and the weak mapping function from the open data vector which is retrieved from the public server; and - sending a request for the secure data vector associated with the user information, said request being signed with the weak private key (K w pri) to the secure server; the secure server being arranged for: - checking the signature using the weak public key (K w pub) upon receiving the request from the computer terminal; - sending the secure data vector comprising the user information, the weak public key (K w pub), the strong mapping key (K s map), the strong mapping function and the random number (K rand) to the computer terminal encrypted with the weak public key (K w pub) upon successful verification of the signature; the computer terminal further being arranged for: - decrypting the secure data vector using (K w pri) upon receiving the encrypted secure data vector from the secure server; generating the strong private key (K s pri) using the biometric value (K bio) together with the strong mapping key (K s map), the strong mapping function and the random number (K rand) from the secure data vector. a secure server for storing a secure data vector, the secure data vector comprises user information, a weak public key (K w pub), a strong mapping key (K s map), a strong mapping function and a random number (K rand); a public server for storing an open data vector, the open data vector comprising the user information, an ambiguity resolution vector, a weak mapping key (K w map) and a weak mapping function; a computer terminal for communicating with the public server and the secure server, the computer terminal being arranged for: - generating a biometric value (K bio) using biometric data received by the computer terminal; - generating a weak private key (K w pri) using said biometric value (K bio), the weak mapping key (K w map) and the weak mapping function from the open data vector which is retrieved from the public server; and - sending a request for the secure data vector associated with the user information, said request being signed with the weak private key (K w pri) to the secure server; - generating a biometric value (K bio) using biometric data received by the computer terminal; - generating a weak private key (K w pri) using said biometric value (K bio), the weak mapping key (K w map) and the weak mapping function from the open data vector which is retrieved from the public server; and - sending a request for the secure data vector associated with the user information, said request being signed with the weak private key (K w pri) to the secure server; the secure server being arranged for: - checking the signature using the weak public key (K w pub) upon receiving the request from the computer terminal; - sending the secure data vector comprising the user information, the weak public key (K w pub), the strong mapping key (K s map), the strong mapping function and the random number (K rand) to the computer terminal encrypted with the weak public key (K w pub) upon successful verification of the signature; the computer terminal further being arranged for: - decrypting the secure data vector using (K w pri) upon receiving the encrypted secure data vector from the secure server; generating the strong private key (K s pri) using the biometric value (K bio) together with the strong mapping key (K s map), the strong mapping function and the random number (K rand) from the secure data vector. - checking the signature using the weak public key (K w pub) upon receiving the request from the computer terminal; - sending the secure data vector comprising the user information, the weak public key (K w pub), the strong mapping key (K s map), the strong mapping function and the random number (K rand) to the computer terminal encrypted with the weak public key (K w pub) upon successful verification of the signature; the computer terminal further being arranged for: - decrypting the secure data vector using (K w pri) upon receiving the encrypted secure data vector from the secure server;