Showing papers by "Robert E. Tarjan published in 1998"
16 Aug 1998
TL;DR: Cox et al. have proposed the use of additive normally distributed values as watermarks, and have sketched an argument showing that, in a certain theoretical model, such watermarks are resistant to collusive attacks, and here the mathematical justification for this claim is filled in.
Abstract: In digital watermarking (also called digital fingerprinting), extra information is embedded imperceptibly into digital content (such as an audio track, a still image, or a movie) This extra information can be read by authorized parties, and other users attempting to remove the watermark cannot do so without destroying the value of the content by making perceptible changes to the content This provides a disincentive to copying by allowing copies to be traced to their original owner Unlike cryptography, digital watermarking provides protection to content that is in the clear It is not easy to design watermarks that are hard to erase, especially if an attacker has access to several differently marked copies of the same base content Cox et al (see IEEE Trans on Image Processing, vol6, no12, p1673-87, 1997) have proposed the use of additive normally distributed values as watermarks, and have sketched an argument showing that, in a certain theoretical model, such watermarks are resistant to collusive attacks Here, we fill in the mathematical justification for this claim
104 citations
23 Feb 1998
TL;DR: This paper is a brief technical survey of the multimedia watermarking landscape and offers possibly acceptable fidelity and robustness against certain types of processing, but are not sufficiently robust against geometric transforms such as scaling and cropping of images.
Abstract: Digital watermarking is a nascent but promising technology that offers protection of unencrypted digital content. This paper is a brief technical survey of the multimedia watermarking landscape. The three main technical challenges faced by watermarking algorithms are fidelity, robustness and security. Current watermarking methods offer possibly acceptable fidelity and robustness against certain types of processing, such as data compression and noise addition, but are not sufficiently robust against geometric transforms such as scaling and cropping of images. Theoretical approaches have been developed that could lead to secure watermarking methods, but substantial gaps remain between theory and practice.
26 citations
TL;DR: In this article, the impact of effective information flow in software ventures is analyzed through a recent case in which a hot, lucrative technology was lost on its way to the marketplace despite the fact that the venture had many components crucial to success, including a proprietary intellectual property position, enormous market demand, a well-qualified, committed team, and sufficient funding.
Abstract: The impact of effective information flow in software ventures is analyzed through a recent case in which a hot, lucrative technology was lost on its way to the marketplace. The failure occurred despite the fact that the venture had many components crucial to success, including a proprietary intellectual property position, enormous market demand, a well-qualified, committed team, and sufficient funding. One reason for this failure is the lack of information flows among several parties critical to the success of the venture. This case suggests that in software markets that operate at breakneck pace and have short development cycles, effective information flow is a first-order priority. These blockages in information flows can stem from the nature of the cultures that are created to produce software ideas, especially proprietary technologies. The case also suggests that information can be affected by the clash between U.S. software market characteristics and Japanese business culture. Fortunately, there are inexpensive solutions that can substantially improve the return on investment, especially foreign investment, in new software technologies.
15 citations
06 Jan 1998
TL;DR: In software markets which operate at breakneck pace and have short development cycles, effective information flow is a first order priority, and information can become impacted by the clash between US software market characteristics and Japanese business culture.
Abstract: The impact of effective information flow in software ventures is analyzed through a recent case in which a hot, lucrative technology was lost on its way to the marketplace. The failure occurred despite the fact that the venture had many components crucial to success, including a proprietary intellectual property position, enormous market demand, a well-qualified, committed team and sufficient funding. One reason for this failure is the lack of information flows among several parties critical to the success of the venture. This case suggests that in software markets which operate at breakneck pace and have short development cycles, effective information flow is a first order priority. These blockages in information flows can stem from the nature of the cultures that are created to produce software ideas, especially proprietary technologies. The case also suggests that information can become impacted by the clash between US software market characteristics and Japanese business culture. Fortunately, there are inexpensive solutions that can substantially improve the return on investment, especially foreign investment, in new software technologies.
11 citations
08 Jul 1998
TL;DR: In this paper, the problem of maintaining persistent lists subject to concatenation and to insertions and deletions at both ends is considered, and a simple implementation of persistent double-ended queues with catenation is presented.
Abstract: We consider the problem of maintaining persistent lists subject to concatenation and to insertions and deletions at both ends. Updates to a persistent data structure are nondestructive-each operation produces a new list incorporating the change while keeping intact the list or lists to which it applies. Although general techniques exist for making data structures persistent, these techniques fail for structures that are subject to operations, such as catenation, that combine two or more versions. In this paper we develop a simple implementation of persistent double-ended queues with catenation that supports all deque operations in constant amortized time.
4 citations