Authentication of an object

A method of authenticating an object, the method including steps of:

• providing coded data portions on a surface of the object, each coded data portion encoding a position of coded data portion on the surface, an identity associated with the object and a signature fragment, the signature fragment being a fragment of a digital signature of at least part of the identity associated with the object;
• receiving from a sensing device indicating data in response to the sensing device sensing a plurality of coded data portions, the indicating data being representative of the data encoded in the plurality of coded data portions sensed by the sensing device;
• determining from the indicating data the identity associated with the object, a plurality of signature fragments encoded in respective coded data portions, and the position of respective coded data portions;
• determining a signature fragment identifier for respective signature fragments from the respective positions;
• determining a determined signature by arranging the plurality of signature fragments according to their respective signature fragment identifiers;
• decrypting the determined signature to obtain a determined identity;
• comparing the identity to the determined identity;
• and
• authenticating the object using the result of the comparison.