The PCBC block cipher mode of operation has many variants, of which one, due to Meyer and Matyas, dates back over 20 years. Whilst a particularly simple variant of PCBC has long been known to be very weak when used for data integrity protection, the Meyer-Matyas variant has not previously been attacked. In this paper we cryptanalyse this mode, and show that it possesses a serious weakness when ...

Semifragile watermarking techniques aim to prevent tampering and fraudulent use of modified images. A semifragile watermark monitors the integrity of the content of the image but not its numerical representation. Therefore, the watermark is designed so that the integrity is proven if the content of the image has not been tampered with, despite some mild processing on the image. However, if part...

DeepFakes are raising significant social concerns. Although various DeepFake detectors have been developed as forensic countermeasures, these still vulnerable to attacks. Recently, a few attacks, principally adversarial succeeded in cloaking images evade detection. However, attacks typical detector-specific designs, which require prior knowledge about the detector, leading poor transferability....

A secure scheme of restrictive partially blind signature is presented. Our proposed scheme has the following advantages. First, the scheme is secure against the one-more signature forgery under the adaptively parallel attack. Second, the issued signatures can be of polynomial number as comparing with the logarithmic number of previous work. At last, the scheme is with less communicational and c...

This paper presents an ID-based serial multisignature scheme using bilinear pairings. We use Hess’s ID-based signature scheme as the base scheme for our multisignature scheme. Our scheme requires a forced verification at every level to avoid the overlooking of the signatures of the predecessors. We show that the scheme is secure against existential forgery under adaptive chosen message attack i...

A stream cipher based algorithm for computing Message Authentication Codes is described. The algorithm employs the internal state of the underlying cipher to minimize the required additional-toencryption computational effort and maintain general simplicity of the design. The scheme appears to provide proper statistical properties, a comfortable level of resistance against forgery attacks in a c...

This paper presents identity based serial and parallel multisignature schemes using bilinear pairings. Our serial multisignature scheme requires a forced verification at every level to avoid the overlooking of the predecessors’ signatures. However, in parallel multisignature scheme the verification of individual signatures is performed by a designated clerk. We show that our schemes are secure ...

A scheme of threshold proxy signature with known signers was proposed by Hwang et al. In their scheme, the receiver can identify the proxy signers that actually generated a proxy signature. Tzeng et al. demonstrated that this signature scheme is insecure and proposed an improvement to mend the information leakage. This paper shows that the improved scheme is still insecure under the original si...

Despite current 802.11i security protocol, wireless networks are vulnerable to Denial of Service (DoS) attacks. Sending a continuous stream of forgery control frames by an attacker can easily flood wireless channel so that the network cannot be available for its associated users. These attacks are possible because wireless control frames do not carry any cryptographic mechanism to detect and di...

Semi-fragile watermarking techniques aim to prevent tampering and fraudulent use of modified images. A semi-fragile watermark monitors the integrity of the content of the image but not its numerical representation. Therefore the watermark is designed so that the integrity is proven if the content of the image has not been tampered with, despite some mild processing on the image. However if part...