Method for the Secure Deposition of Digital Data, Associated Method for Recovering Digital Data, Associated Devices for Implementing Methods, and System Comprising Said Devices

A method for recovering data, according to which:

• an addressee recovers from a storage support data encrypted with a transfer key, and a transfer key encrypted with the key of a third party,
• the addressee authenticates himself/herself to the third party,
• the addressee sends the encrypted transfer key to the third party,
• after having authenticated the addressee, the third party decrypts the encrypted transfer key using his/her key and returns the transfer key to the addressee,
• the addressee decrypts the encrypted data using the transfer key.

A device for the secure deposition of data, comprising:

• a random number generator for generating a random transfer key,
• first computation means for encrypting data with the transfer key,
• second computation means for encrypting the transfer key using the key of a third party, and
• means for storing the encrypted data and the encrypted transfer key on a storage support accessible to an addressee of the data.