Multiple-Identity Image Attacks Against Face-based Identity Verification

Understand

Facial verification systems are vulnerable to poisoning attacks that make use of multiple-identity images (MIIs)---face images stored in a database that resemble multiple persons, such that novel images of any of the constituent persons are verified as matching the identity of the MII.

• Research on this mode of attack has focused on defence by detection, with no explanation as to why the vulnerability exists.
• New quantitative results are presented that support an explanation in terms of the geometry of the representations spaces used by the verification systems.
• In the spherical geometry of those spaces, the angular distance distributions of matching and non-matching pairs of face representations are only modestly separated, approximately centred at 90 and 40-60 degrees, respectively.