Digital identification and missing fingers

Jeremy Phillips

Today’s online Official Journal of the European Union features the Commission Decision of 9 October 2009 laying down specifications for the resolution and use of fingerprints for biometric identification and verification in the Visa Information System (notified under document C(2009) 7435). Don’t take its text too seriously if you are reading it in English, since “only the Bulgarian, Czech, Dutch, Estonian, Finnish, French, German, Greek, Hungarian, Italian, Latvian, Lithuanian, Maltese, Polish, Portuguese, Romanian, Slovak, Slovenian, Spanish and Swedish texts are authentic” [this is not a joke]. Datonomy hopes that the European Court of Justice will never be called upon to rule on its interpretation in the event that there exists any inconsistency between the Maltese and Lithuanian texts.

This opinion deals with that most personal of data, the fingerprint, which it seems is coming back into fashion. For those of you who have ever wondered, this Opinion discusses some of the most interesting facets of record-keeping and identification by means of fingerprints. In particular:

1. Resolution of fingerprints

The Central Visa Information System (CS-VIS) shall receive fingerprint images of ten fingers flat of a nominal resolution only of 500 dpi (with an acceptable deviation of +/– 5 dpi) with 256 grey levels.

2. Use of ten fingerprints for biometric identifications and searches

CS-VIS shall perform biometric searches (biometric identifications) with ten fingers flat. However, when fingers are missing, these shall be identified accordingly as specified by the ANSI/NIST-ITL 1-2000 standard ( 1 ) and the remaining fingers, if any [Who added “if any”? For goodness’ sake, if there aren’t any remaining fingers, then there’s nothing to take fingerprints from — or have I missed something?], shall be used.

3. Use of four fingerprints for biometric verifications

CS-VIS shall be able to perform biometric verifications for accessing data with four fingers flat. When available, fingerprints from the following fingers of either the right hand or the left hand [Just the right or the left? No provision has been made for the identification of persons with three or more hands. I assume that the four fingers may be drawn from more than one hand, this being an ‘and/or’ rather than an ‘either/or’] shall be used: the index finger (NIST identification 2 or 7), middle finger (NIST identification 3 or 8), ring finger (NIST identification 4 or 9), little finger (NIST identification 5 or 10).

For ergonomic, standardisation and visualisation purposes, fingerprints from the same hand shall be used, starting with the right hand.

The finger-position shall be identified for each individual fingerprint image as specified by the ANSI/NIST-ITL 1-2000 standard.

When such finger-position identification is not possible or it proves to be erroneous, national systems may request verifications in CS-VIS involving the use of ‘permutations’.

Missing or bandaged fingers shall always be identified as specified by the ANSI/NIST-ITL 1-2000 standard and the VIS Interface Control Document.

4. Use of one or two fingerprints for biometric verifications

Member States may decide to use one or two fingerprints flat for biometric verifications, instead of four fingerprints.

The following fingers shall be used by default:
(a) One finger: index finger (NIST identification 2 or 7),
(b) Two fingers: index finger (NIST identification 2 or 7) and middle finger (NIST identification 3 or 8).

In addition the following fingers may be used:
(a) One finger: thumb (NIST identification 1 or 6) or middle finger (NIST identification 3 or 8),
(b) Two fingers:
(i) index finger (NIST identification 2 or 7) and ring finger (NIST identification 4 or 9) or
(ii) middle finger (NIST identification 3 or 8) and ring finger (NIST identification 4 or 9).

For ergonomic, standardisation and visualisation purposes, fingerprints from the same hand shall be used, starting with the right hand.

The finger-position shall be identified for each individual fingerprint image as specified by the ANSI/NIST-ITL 1-2000 standard.

When such finger-position identification is not possible or it proves to be erroneous, national systems may request verifications in CS-VIS involving the use of ‘permutations’.

Missing or bandaged fingers shall always be identified as specified by the ANSI/NIST-ITL 1-2000 standard and the VIS Interface Control Document”.

Leave a Reply

Your email address will not be published. Required fields are marked *