Apparatus, computer program and method

A method comprising:

• receiving from a submitter, over a network, a data item of a first data type, wherein the data item comprises a plurality of components;
• sequentially receiving the plurality of components of the data item;
• and
• for each component in succession in the sequence:
• removing non-significant content from the component of the data item;
• generating a data item of a second data type from the sequentially received plurality of components;
• generating a hash of the generated data item;
• and
• providing the hash for signing.

A non-transitory computer-readable storage medium comprising executable instructions, which when executed by at least one processor, cause the at least one processor to:

• receive from a submitter, over a network, a data item of a first data type, wherein the data item comprises a plurality of components;
• sequentially receive the plurality of components of the data item;
• and
• for each component in succession in the sequence:
• remove non-significant content from the component of the data item;
• generate a data item of a second data type from the sequentially received plurality of components;
• generate a hash of the generated data item;
• and
• provide the hash for signing.