Object authentication

Abstract

An apparatus for authenticating an object is disclosed. The apparatus receives from a sensing device indicating data. The indicating data is formed by the sensing device in response to sensing a plurality of coded data portions on a surface of the object. Each coded data portion encodes 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. A processor then determines 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, determines a signature fragment identifier for respective signature fragments from the respective positions, determines a determined signature by arranging the plurality of signature fragments according to their respective signature fragment identifiers, decrypts the determined signature to obtain a determined identity, compares the identity to the determined identity, and then authenticates the object using the result of the comparison.

1 . Apparatus for authenticating an object, the apparatus including:
 means for receiving from a sensing device indicating data, the indicating data being formed by the sensing device in response to sensing a plurality of 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;   means for 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;   means for determining a signature fragment identifier for respective signature fragments from the respective positions;   means for determining a determined signature by arranging the plurality of signature fragments according to their respective signature fragment identifiers;   means for decrypting the determined signature to obtain a determined identity;   means for comparing the identity to the determined identity; and   means for authenticating the object using the result of the comparison.   
     
     
         2 . Apparatus according to  claim 1  wherein the signature is further a digital signature of padding, the padding being generated from the identity associated with the object, and the means for decrypting decrypts the determined signature to obtain the determined identity and a determined padding. 
     
     
         3 . Apparatus according to  claim 1  further including:
 means for generating authentication data indicative of success or failure of the authentication; and   means for transferring the authentication data to a user.   
     
     
         4 . Apparatus according to  claim 1 , wherein the digital signature is generated from at least part of the identity by encrypting at least part of the identity using a private key, and the decryption uses a public key complimentary to the private key to obtain the determined identity. 
     
     
         5 . Apparatus according to  claim 4 , wherein the private and public keys are stored and retrieved by indexing the keys by the identity. 
     
     
         6 . Apparatus according to  claim 1 , wherein the means for receiving includes one or more of:
 a communications network;   the Internet;   a mobile phone network; and,   a wireless connection.   
     
     
         7 . Apparatus according to  claim 1 , wherein the coded data is provided substantially coincident with visible human-readable information. 
     
     
         8 . Apparatus according to  claim 1 , wherein the coded data is arranged in accordance with at least one layout having n-fold rotational symmetry, where n is at least two, the layout including n identical sub-layouts rotated 1/n revolutions apart about a centre of rotation, at least one sub-layout including rotation-indicating data that distinguishes that sub-layout from each other sub-layout. 
     
     
         9 . Apparatus according to  claim 1 , wherein the coded data is arranged in accordance with at least one layout having n-fold rotational symmetry, where n is at least two, the layout encoding orientation-indicating data comprising a sequence of an integer multiple m of n symbols, where m is one or more, each encoded symbol being distributed at n locations about a centre of rotational symmetry of the layout such that decoding the symbols at each of the n orientations of the layout produces n representations of the orientation-indicating data, each representation comprising a different cyclic shift of the orientation-indicating data and being indicative of the degree of rotation of the layout.