IMPEDING DATA ACCESS

A computer implemented method of protecting data in a message for communication from a sender to a receiver, the sender and receiver sharing a secret, the method including splitting the message into a plurality of ordered message blocks, the order being a proper order such that an aggregation of the blocks in the proper order constitutes the message; generating a hash value for each message block, each hash value being generated on the basis of at least a content of the block and the secret; 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 the hash value for the block and a position of the block in the proper order; communicating the blocks to the receiver in an order different to the proper order so as to obfuscate the message; and communicating the encoded indications to the receiver such that the blocks can be reassembled by the receiver in the proper order on the basis of the shared secret.