Blockchain based privacy enhanced outsourced data storage

Computer equipment comprising:

• memory comprising one or more memory units;
• and
• processing apparatus comprising one or more processing units,
• wherein the memory stores code arranged to run on the processing apparatus, the code being configured so as when run on the processing apparatus, the processing apparatus performs a method of:
• i) requesting, by a first entity from a second entity, a root value (R′) of a Merkle tree (T) calculated based on a variation of at least one of a plurality of sub-portions of a portion of data (D);
• or
• providing, from a second entity to a first entity, the root value (R′) of a Merkle tree (T) calculated based on a variation of at least one of a plurality of sub-portions of a portion of data (D);
• and
• ii) comparing, by the first entity, a root value (R′) received from the second entity with a pre-calculated root value calculated by the first entity and deeming verification of the portion of data (D) to be successful if the received root value (R′) matches the pre-calculated root value, or unsuccessful if the received root value (R′) does not match the pre-calculated root value.

A computer program embodied on non-transitory computer-readable storage media and configured so as, when run on one or more processors, the one or more processors perform a method of

• i) requesting, by a first entity from a second entity, a root value (R′) of a Merkle tree (T) calculated based on a variation of at least one of a plurality of sub-portions of a portion of data (D);
• or
• providing, from a second entity to a first entity, the root value (R′) of a Merkle tree (T) calculated based on a variation of at least one of a plurality of sub-portions of a portion of data (D);
• and
• ii) comparing, by the first entity, a root value (R′) received from the second entity with a pre-calculated root value calculated by the first entity and deeming verification of the portion of data (D) to be successful if the received root value (R′) matches the pre-calculated root value, or unsuccessful if the received root value (R′) does not match the pre-calculated root value.