Abstract: A method is presented for distributing cryptographic keys in a hierarchized network including at least one device in charge of a higher group of devices, wherein at least one of the devices of the higher group of devices is also in charge of a lower group of devices. The method includes the steps of: a) storing a set of identifiers particular to the higher group, an identifier particular to the device in charge, an identifier per device in charge of a lower group, each identifier being unique; storing a root cryptographic key; c) providing a root cryptographic key to each device in charge of a lower group using a first non-reversible cryptographic function; d) providing at least one transport cryptographic key to each member of said higher group of devices using a second non-reversible cryptographic function.

Abstract: A method is presented for distributing cryptographic keys in a hierarchized network including at least one device in charge of a higher group of devices, wherein at least one of the devices of the group of devices is also in charge of a lower group of devices.

Abstract: An authentication method between a client (2) and a server (4) sharing a secret (6) includes the following steps: the server (4) generates at least one random value (40); the server (4) computes a first encrypted value (46); the server (4) concatenates the random value (40) and the first encrypted value (46) to form a challenge (10); the client (2) extracts the random value (40) and the first encrypted value (46) from the challenge (10); the client (2) computes a second encrypted value (48); the client (2) compares the first (46) and second (48) encrypted values; and the server (4) is authenticated by the client (2) if the first (46) and second (48) encrypted values match.