To delegate authority for cryptographic communication without increasing the risk of leaking a device key. A system and method including a first communication apparatus and a managing apparatus allowing the first communication apparatus to perform cryptographic communication with an external at least one second communication apparatus. The managing apparatus includes: storing a first device key shared with the second communication apparatus; generating a computation by passing the first device key read from the stored keys to a keyed one-way function, to generate a computed result as a second device key; and outputting the second device key and a key of the one-way function to the first communication apparatus. The first communication apparatus transmits a key of a one-way function to the second communication apparatus causing the second communication apparatus to perform a computation which generates a second device key, and which performs a cryptographic communication with a second communication apparatus.