the invention concerns a method for guaranteeing certification of a user &# 39 ; s public key by reducing requests to key - certifying appropriate authorities . more particularly , the invention concerns a method for managing a public key of a user capable of being implemented in an asymmetric cryptosystem . according to the invention , a certification , or validation of the correspondence between a public key and a user , is performed by a validating entity , a provider separate from the certifying authority via a validation step . the password is verifiable by the validating entity , but without the latter being aware of it .