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A Maximum Likelihood Watermark Decoding Scheme, Wenming Lu, Wanqing Li, Rei Safavi-Naini, Philip Ogunbona
A Maximum Likelihood Watermark Decoding Scheme, Wenming Lu, Wanqing Li, Rei Safavi-Naini, Philip Ogunbona
Reihaneh Safavi-Naini
Based on the observation that an attack applied on a watermarked image, from a decoding point of view, modifies the distribution of the detection values away from the ideal distribution (without attack) for corresponding watermarking scheme, we propose a generic maximum likelihood decoding scheme by approximating the distribution with a finite Gaussian mixture model. The parameters of the model are estimated using expectation-maximization algorithm. The scheme allows the decoding to be automatically adapted to attacks that the watermarked images have undergone and, in consequence, to improve the decoding accuracy. Experiments on a QIM based watermarking system have clearly verified the …
Sharing Digital Rights With Domain Licensing, N. P. Sheppard, R. Safavi-Naini
Sharing Digital Rights With Domain Licensing, N. P. Sheppard, R. Safavi-Naini
Reihaneh Safavi-Naini
Sharing of multimedia content is a common practice that, combined with appropriate business models, need not be detrimental to the interests of content providers. Existing digital rights management systems, however, support only relatively limited sharing of content between multimedia terminals, resulting in inconvenience and frustration for end-users of rights-managed content. In this paper, we propose to combine the notion of an "authorised domain" with an "environment role" to permit end-users to share access to multimedia content within the constraints expressed in a domain licence. We describe how a variety of different business models can be supported using domain licences, and …
Performance Measurement Of Watermark Embedding Patterns, R. Scealy, R. Safavi-Naini, N. P. Sheppard
Performance Measurement Of Watermark Embedding Patterns, R. Scealy, R. Safavi-Naini, N. P. Sheppard
Reihaneh Safavi-Naini
Segmented watermarking is an approach to multiple watermarking that can be used to acknowledge the contribution of multiple authors or to embed a fingerprint code-word, but is susceptible to cropping attacks that discard portions of the watermarked media. Careful selection of the watermark embedding pattern can increase the resilence of a segmented watermark in the presence of cropping attacks. In this paper, we consider performance measures for embedding patterns and compare the performance of several proposed embedding patterns using these measures.
Location Privacy In Mobile Ip, Rungrat Wiangsripanawan, R. Safavi-Naini, Willy Susilo
Location Privacy In Mobile Ip, Rungrat Wiangsripanawan, R. Safavi-Naini, Willy Susilo
Reihaneh Safavi-Naini
Several security issues arise, due to the design of the mobile IP and its deployment in conjunction with other network protocols. Most of the work on the security of mobile IP has focused on authentication of the control packet and the confidentiality of the content in the protocol, and there are not many proposals in the area of location privacy. In this paper, we propose a method to provide location privacy for mobile IP users. We present two protocols that use an overlay network approach, and designed particularly for mobile IP. We employ universal re-encryption and extend it to n-out-of-n …
A New And Efficient Fail—Stop Signature Scheme, Willy Susilo, R. Safavi-Naini, M. Gysin, Jennifer Seberry
A New And Efficient Fail—Stop Signature Scheme, Willy Susilo, R. Safavi-Naini, M. Gysin, Jennifer Seberry
Reihaneh Safavi-Naini
Security of ordinary digital signature schemes relies on a computational assumption. Fail-stop signature schemes provide security for a sender against a forger with unlimited computational power by enabling the sender to provide a proof of forgery, if it occurs. In this paper, we give an efficient fail-stop signature scheme that uses two hard problems, discrete logarithm and factorisation, as the basis of receiver's security. We show that the scheme has provable security against adaptively chosen message attack and is the most efficient scheme with respect to the ratio of the message length to the signature length. The scheme provides an …
Securing Mobile Ip Enabled Laptop, Rungrat Wiangsripanawan, R. Safavi-Naini, Willy Susilo
Securing Mobile Ip Enabled Laptop, Rungrat Wiangsripanawan, R. Safavi-Naini, Willy Susilo
Reihaneh Safavi-Naini
Mobile IP Onternet Protocol) enables access to the Internet anywhere with one IP address, hence, providing the flexibility that is required by today’s growing mobile work force. Deploying Mobile IP introduces new security h a t s that if not carefully addressed can have severe consequences for home organizations. IPSec is a commonly used protection mechanism that is employed in this context. IPSec requires a flexible key management scheme to provide cryptographic keys to communicating entities. A commonly used public key based key management system is SKIP (Simple Key-Management for Internet Protocols). In this paper we consider the scenario where …
New Results On Frame-Proof Codes And Traceability Schemes, R. Safavi-Naini, Yejing Wang
New Results On Frame-Proof Codes And Traceability Schemes, R. Safavi-Naini, Yejing Wang
Reihaneh Safavi-Naini
In this correspondence we derive lower bounds on the maximum number of codewords in a class of frame-proof codes and traceability schemes, and give constructions for both with more codewords than the best known.
Import/Export In Digital Rights Management, R. Safavi-Naini, N. P. Sheppard, Takeyuki Uehara
Import/Export In Digital Rights Management, R. Safavi-Naini, N. P. Sheppard, Takeyuki Uehara
Reihaneh Safavi-Naini
The inherently controlled nature of digital rights management systems does little to promote inter-operability of systems provided by different vendors. In this paper, we consider import and export functionality by which multimedia protected by one digital rights management regime can be made available to a multimedia device that supports a different digital rights management regime, without compromising the protection afforded to the content under the original regime. We first identify specific issues to be addressed by developers of digital rights management import/export regimes and outline a variety of methods by which these regimes may be implemented. We then apply our …
A Scalable And Oblivious Digital Watermarking For Images, W. Lu, R. Safavi-Naini, Takeyuki Uehara, Wanqing Li
A Scalable And Oblivious Digital Watermarking For Images, W. Lu, R. Safavi-Naini, Takeyuki Uehara, Wanqing Li
Reihaneh Safavi-Naini
Scalable compression algorithms, such as JPEG, can compress images to different quality or resolution levels so that the target systems with different display capabilities, can display the image. Digital watermarking is widely used for protection of copyright and identification of ownership on digital images. It is desirable to have scalable watermarking systems, where the watermark is detectable when the watermarked image is at low quality or low resolution levels. This paper presents an oblivious block-based spread-spectrum-like watermarking system which is robust against scalable JPEG compression, cropping and shifting. The system is secure against the common watermarking attacks. Experimental results support …
High-Capacity Steganography Using A Shared Colour Palette, G. Brisbane, R. Safavi-Naini, P. Ogunbona
High-Capacity Steganography Using A Shared Colour Palette, G. Brisbane, R. Safavi-Naini, P. Ogunbona
Reihaneh Safavi-Naini
Seppanen, Makela and Keskinarkaus (SMK) have proposed a high-capacity steganographic technique to conceal information within a colour image. The technique is significant because of the high volume of data that is embedded into pixels but it results in a high level of noise and so the quality of the resulting image is not acceptable. A new type of coding structure is proposed, which maintains a high capacity but lowers the level of noise. Secondly, an adaptive algorithm is used to identify pixel values that have a high capacity to distortion ratio. Also the maximum size of the coding structures is …