With rapid progress in Internet and digital imaging technology, there are more and more ways to easily create, publish, and distribute images. Considered the first book to focus on the relationship between digital imaging and privacy protection, Visual Cryptography and Secret Image Sharing is a complete introduction to novel security methods and sharing-control mechanisms used to protect against unauthorized data access and secure dissemination of sensitive information. Image data protection and image-based authentication techniques offer efficient solutions for controlling how private data and images are made available only to select people. Essential to the design of systems used to manage images that contain sensitive data-such as medical records, financial transactions, and electronic voting systems-the methods presented in this book are useful to counter traditional encryption techniques, which do not scale well and are less efficient when applied directly to image files. An exploration of the most prominent topics in digital imaging security, this book discusses: Potential for sharing multiple secrets Visual cryptography schemes-based either on the probabilistic reconstruction of the secret image, or on different logical operations for combining shared images Inclusion of pictures in the distributed shares Contrast enhancement techniques Color-image visual cryptography Cheating prevention Alignment problems for image shares Steganography and authentication In the continually evolving world of secure image sharing, a growing number of people are becoming involved as new applications and business models are being developed all the time. This contributed volume gives academicians, researchers, and professionals the insight of well-known experts on key concepts, issues, trends, and technologies in this emerging field.

With rapid progress in Internet and digital imaging technology, there are more and more ways to easily create, publish, and distribute images. Considered the first book to focus on the relationship between digital imaging and privacy protection, Visual Cryptography and Secret Image Sharing is a complete introduction to novel security methods and sharing-control mechanisms used to protect against unauthorized data access and secure dissemination of sensitive information.

Image data protection and image-based authentication techniques offer efficient solutions for controlling how private data and images are made available only to select people. Essential to the design of systems used to manage images that contain sensitive data-such as medical records, financial transactions, and electronic voting systems-the methods presented in this book are useful to counter traditional encryption techniques, which do not scale well and are less efficient when applied directly to image files.

An exploration of the most prominent topics in digital imaging security, this book discusses:

• Potential for sharing multiple secrets
• Visual cryptography schemes-based either on the probabilistic reconstruction of the secret image, or on different logical operations for combining shared images
• Inclusion of pictures in the distributed shares
• Contrast enhancement techniques
• Color-image visual cryptography
• Cheating prevention
• Alignment problems for image shares
• Steganography and authentication

In the continually evolving world of secure image sharing, a growing number of people are becoming involved as new applications and business models are being developed all the time. This contributed volume gives academicians, researchers, and professionals the insight of well-known experts on key concepts, issues, trends, and technologies in this emerging field.

These proceedings contain the papers selected for presentation at the 23rd Inter- tional Information Security Conference (SEC 2008), co-located with IFIP World Computer Congress (WCC 2008), September 8-10, 2008 in Milan, Italy. In - sponse to the call for papers, 143 papers were submitted to the conference. All - pers were evaluated on the basis of their signi?cance, novelty, and technical quality, and reviewed by at least three members of the program committee. Reviewing was blind meaning that the authors were not told which committee members reviewed which papers. The program committee meeting was held electronically, holding - tensive discussion over a period of three weeks. Of the papers submitted, 42 full papers and 11 short papers were selected for presentation at the conference. A conference like this just does not happen; it depends on the volunteer efforts of a host of individuals. There is a long list of people who volunteered their time and energy to put together the conference and who deserve acknowledgment. We thank all members of the program committee and the external reviewers for their hard work in the paper evaluation. Due to the large number of submissions, p- gram committee members were required to complete their reviews in a short time frame. We are especially thankful to them for the commitment they showed with their active participation in the electronic discussion

These proceedings contain the papers selected for presentation at the 23rd Inter- tional Information Security Conference (SEC 2008), co-located with IFIP World Computer Congress (WCC 2008), September 8-10, 2008 in Milan, Italy. In - sponse to the call for papers, 143 papers were submitted to the conference. All - pers were evaluated on the basis of their signi?cance, novelty, and technical quality, and reviewed by at least three members of the program committee. Reviewing was blind meaning that the authors were not told which committee members reviewed which papers. The program committee meeting was held electronically, holding - tensive discussion over a period of three weeks. Of the papers submitted, 42 full papers and 11 short papers were selected for presentation at the conference. A conference like this just does not happen; it depends on the volunteer efforts of a host of individuals. There is a long list of people who volunteered their time and energy to put together the conference and who deserve acknowledgment. We thank all members of the program committee and the external reviewers for their hard work in the paper evaluation. Due to the large number of submissions, p- gram committee members were required to complete their reviews in a short time frame. We are especially thankful to them for the commitment they showed with their active participation in the electronic discussion

The 4th International Conference on Security in Communication Networks 2004 (SCN2004)washeldatthe DioceseHall oftheArchdioceseofAmal?-Cavade Tirreni and the Armorial Bearings Hall of the Archbishop Palace in Amal?, Italy, on September 8 10, 2004. Previous conferences also took place in Amal? in 1996, 1999 and 2002. The conference aimed at bringing together researchers in the ?elds of cr- tography and security in communication networks to foster cooperation and the exchange of ideas. The main topics included all technical aspects of data security, including: anonymity, authentication, blockciphers, complexity-basedcryptography, cry- analysis, digital signatures, distributed cryptography, hash functions, identi?- tion, implementations, keydistribution, privacy, publickeyencryption, threshold cryptography, and zero knowledge. The Program Committee, consisting of 21 members, considered 79 papers and selected 26 for presentation; one of them was withdrawn by the authors. These papers were selected on the basis of originality, quality and relevance to cryptography and security in communication networks. Due to the high number of submissions, paper selection was a di?cult and challenging task, and many good submissions had to be rejected. Each subm- sion was refereed by at least three reviewers and some had four reports or more. We are very grateful to all the program committee members, who devoted much e?ort and valuable time to read and select the papers. In addition, we gratefully acknowledge the help of colleagues who reviewed submissions in their areas of expertise. They are all listed on page VII and we apologize for any inadvertent omissions. These proceedings include the revised versions of the 26 accepted papers andtheabstractoftheinvitedtalkbyBartPreneel(ECRYPT: theCryptographic Research Challenges for the Next Decade)."

This book constitutes the thoroughly refereed post-proceedings of the Third International Conference on Security in Communication Networks, SCN 2002, held in Amalfi, Italy in September 2002. The 24 revised full papers presented together with two invited papers were carefully selected from 90 submissions during two rounds of reviewing and revision. The papers are organized in topical sections on forward security, foundations of cryptography, key management, cryptanalysis, systems security, digital signature schemes, zero knowledge, and information theory and secret sharing.