No abstract

Abstract. Provenance is a record that describes the people, institutions, entities, and activities involved in producing, influencing, or delivering a piece of data or a thing. In particular, the provenance of information is crucial in deciding whether information is to be trusted. PROV is a recent W3C specification for sharing provenance over the Web. However, provenance records may expose confidential information, such as identity of agents or specific attributes of entities or activities. It is therefore essential for confidential information to be obscured before sharing provenance. This paper describes PROV-GTS, a provenance graph transformation system, whose principled definition is based on PROV properties, and which seeks to avoid false independencies and false dependencies. PROV-GTS is shown to preserve graph integrity, to be terminating and to be confluent.

Abstract-In this paper a new non-blind luminance-based color image watermarking technique is proposed. The original 512×512 color host image is divided into 8×8 blocks, and each block is converted to YC b C r color space. A 32×32 monochrome image is used as a watermark and embedded in the selected blocks of the original image. The selected blocks must have log-average luminance that is closer to the log-average luminance of the image. DCT transform is applied to the Y component of each selected block. Each four values of the watermark image are embedded into each selected block of the host image.The watermark values are embedded in the first four AC coefficients leaving the DC value unchanged. The watermark is extracted from the watermarked image using the same selected blocks and DCT coefficients that have been used in the embedding process. This approach is tested against variety of attacks and filters: such as, highpass, lowpass, Gaussian, median, salt and peppers, and JPEG compression. The proposed approach shows a great ability to preserve the watermark against these attacks.

No abstract