Robust storage

A data storage system for a motor vehicle comprising:

• at least one peripheral circuit configured to transmit, to at least two secure circuits, one or more data values to be stored;
• wherein the at least two secure circuits are each configured to search for a proof of work;
• wherein, as soon as a potential proof of work has been found by at least a first circuit of the two secure circuits, the first circuit is further configured to transmit the found potential proof of work to each of the other secure circuits among the at least two secure circuits;
• wherein the other secure circuits are further configured to verify the potential proof of work;
• and
• wherein, if the potential proof of work effectively matches the proof of work searched for, the at least two secure circuits are further configured to store the one or more data values in a block of a blockchain, the one or more data values being stored in association with an identification value identifying an immediately preceding block in the blockchain, the proof of work, and an identification value identifying a current block, the identification value of the current block being calculated based on the identification value of the immediately preceding block, on the one or more data values, and on the proof of work.

A secure circuit comprising:

• a number generator configured to generate candidate values;
• a processor configured to verify whether each candidate value generated matches a target challenge value;
• a non-volatile memory storing a blockchain;
• wherein the secure circuit is configured to:
• transmit, when a candidate value matches the target challenge value, the candidate value as being a proof of work to other secure circuits, or
• receive a proof of work transmitted by another secure circuit;
• wherein the processor is further configured to verify whether the proof of work matches the target challenge value;
• wherein the non-volatile memory is further configured to store, in a current block of the blockchain, one or more data values in association with an identification value identifying a block immediately preceding the current block, an identification value identifying the current block, and the proof of work;
• wherein the processor being further configured to generate a value of the current block based on the identification value of the immediately preceding block, on the one or more data values, and on the proof of work.