Robust image hashing

TLDR

The proliferation of digital images creates problems for managing large image databases, indexing individual images, and protecting intellectual property. This paper introduces a novel image indexing technique that may be called an image hash function. The algorithm employs randomized signal processing to compress images into non‑reversible random binary strings, providing a cryptographic‑style message authentication code that is robust to compression, geometric distortions, and other attacks. The method minimizes collision probability even against adversarial inputs.

Abstract

The proliferation of digital images creates problems for managing large image databases, indexing individual images, and protecting intellectual property. This paper introduces a novel image indexing technique that may be called an image hash function. The algorithm uses randomized signal processing strategies for a non-reversible compression of images into random binary strings, and is shown to be robust against image changes due to compression, geometric distortions, and other attacks. This algorithm brings to images a direct analog of message authentication codes (MACs) from cryptography, in which a main goal is to make hash values on a set of distinct inputs pairwise independent. This minimizes the probability that two hash values collide, even, when inputs are generated by an adversary.