Patent ID: 11924327
Assignee: BRITISH TELECOMMUNICATIONS PUBLIC LIMITED COMPANY
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A computer system comprising:
a processor and memory storing computer program code for protecting data in a message for communication from a sender to a receiver, the sender and the receiver sharing a secret, by:
splitting the message into a number of ordered message blocks, the order being a proper order such that an aggregation of the blocks in the proper order constitutes the message, and the blocks being of variable size, with sensitive parts of the message stored in smaller blocks as compared to non-sensitive parts of the message;
generating, for each block, an encoded indication of a position of the block in the proper order of blocks, the encoding being reversible and based on at least a hash value for the block, a secret shared between the sender and the receiver, and a position of the block in the proper order;
communicating the blocks and the encoded indications to the receiver, the blocks being communicated in an order different than the proper order so as to obfuscate the message, such that the blocks can be reassembled by the receiver in the proper order on the basis of the shared secret; and
wherein the number of ordered message blocks is determined on the basis of a performance analysis of a computing device of the sender or the receiver, the performance analysis determining a maximum number of hashing operations that can be performed by the computing device while satisfying a predetermined performance criterion for the computing device.