A safe card system comprising: a plurality of safe cards, at least one safe card reader and a service provider computer. Each safe card: Capable of generating at a specific time a temporary number based on combination of a first number representing at least one biometric identifier, and a temporary second number, and a card signal based on the temporary number; The at least one safe card reader capable of reading the card signal, and converting the card signal into a card reader number, The service provider: Capable of drawing at a specific time at least one fifth number associated with said time, generating at least one sixth number derived from the fifth numbers, and comparing the sixth numbers to the card reader number so as to allow service to the safe card when a sixth number is identical to the card reader number.