Digital Signature Based Control Integrity for JPEG HDR Images

Abstract

“A ship is always safe at the shore, but that is not what it is built for.”-Albert Einstein. The same philosophy is applied to picture files saved safety on storage devices. This is, however, not always the case. Sharing and exchanging image data through computer networks affect their security. The issue that arises is how to protect these visual contents from malicious attacks. To alleviate this problem, an image verification feature can be exploited to automatically verify the integrity of these contents. In this way, users can detect any intentional corruptions, which can occur at any time during transmission.

In the present work, we propose a selective authentication system adapted to HDR images. The main contribution consists in verifying the integrity of several parts from JPEG-HDR files by using a content-based watermarking method. Specifically, a couple of local digital thumbprint and digital signature is calculated based on the SHA-2(256 bits) secure hash algorithm. Then, a verification process is performed by using two different secret keys (private and public RSA keys). Our HDR image verification scheme is applied in the DCT transform domain and maintains backwards compatibility with the legacy JPEG standard. A performance analysis and comparison with related work demonstrate the effectiveness of the proposed approach.