Patent WO-2022259202-A1 (WO)
Title: Computation method for executing protocols based on secret information, performed by means of equipment with secure hardware
Inventor: GUERRIERI ROBERTO
IPC: H04L9/32
Filed: 2022-06-09
Abstract: A computation method for executing protocols based on secret information, by means of electronic processing means comprising at least one secure computation device (DSC), is described. The at least one secure computation device DCS comprises at least one secure portion, that is a device architecture portion which is separate from a remaining part of a processing system with which such a device is configured to interoperate by means of the exchange of results of non-reversible encryption functions. The secure computation device, DCS, is further configured to execute software computation programs that are certified. The method comprises the steps of: generating, in the aforesaid secure portion of the secure computation device DCS, a secret piece of information represented by a first number string, adapted to be used as basis of encryption protocols; the secure computation device DCS then generating a second string associated with the aforesaid first string (representative of a secret piece of information) by means of a public key signature protocol. The method further provides preparing, in the secure computation device DCS, at least two states which can be identified by means of respective identifiers stored in the device; such at least two states comprise a first open state and a second controlled state. In the first open state, the control of at least certain parts of the secure computation device, DCS, may be taken on by at least one player performing a procedure of taking control. In the second controlled state, the secure computation device DCS may operate only on the basis of orders/commands of at least one player who has already taken control of the secure computation device DCS. The method then comprises the step of executing at least one protocol based on secret information, by the secure computation device, on the basis of orders, commands or instructions contained in the operating software on the DCS, as expected by at least one player who has already taken control of the secure computation device, DCS, or of at least a portion of such a secure computation device, DCS. The aforesaid procedure of taking control comprises the following steps: - while the secure computation device, DCS, is in the aforesaid first open state, sending a public key based on a predetermined encryption protocol, by the at least one player that intends to take control; - the at least one player intending to take control communicating to the secure computation device, DCS, that control has been taken, by means of a message signed by the private key associated with the aforesaid public key of the aforesaid player; - the secure computation device verifying that the received message is correctly signed by the correct private key; - if the results of such a check are positive, entering the second controlled state, in which the aforesaid at least one player has taken control of the appropriate device area, and in which the whole secure computation device, or at least a portion thereof, such as a specific storage location, may be accessed and used only by the aforesaid player who has taken control.