National Institute of Standards and Technology における超伝導研究及び生活

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

A new 1D chaotic system for image encryption

A chaos-based symmetric image encryption scheme using a bit-level permutation

A new color image encryption using combination of the 1D chaotic map

Threshold visual secret sharing by random grids

Visual secret sharing by random grids revisited

A secret sharing scheme allows a secret to be shared among a set of participants, P, such that only authorized subsets of P can recover the secret, but any unauthorized subset cannot recover the secret. In 1995, Naor and Shamir proposed a variant of secret sharing, called visual cryptography, where the shares given to participants are xeroxed onto transparencies. If X is an authorized subset of P, then the participants in X can visually recover the secret image by stacking their transparencies together without performing any computation. In this paper, we address the issue of cheating by dishonest participants, called cheaters, in visual cryptography. The experimental results demonstrate that cheating is possible when the cheaters form a coalition in order to deceive honest participants. We also propose two simple cheating prevention visual cryptographic schemes.

Cheating in Visual Cryptography

Efficient multi-secret image sharing based on Boolean operations

A wavelet-based copyright-proving scheme that does not require the original image for logo verification is proposed in this paper. The scheme is strong enough to resist malicious manipulations of an image including blurring, JPEG compression, noising, sharpening, scaling, rotation, cropping, scaling-cropping, and print-photocopy-scan attacks. The proposed scheme is also resistant to StirMark and unZign attacks and it is not only a robust method but also a lossless one. Experiments are conducted to show the robustness of this method. Moreover, cryptographic tools, such as digital signature and timestamp, are introduced to make copyright proving publicly verifiable.

Tzung-Her Chen

Papers

Threshold visual secret sharing by random grids

Visual secret sharing by random grids revisited

Cheating in Visual Cryptography

Efficient multi-secret image sharing based on Boolean operations

A publicly verifiable copyright-proving scheme resistant to malicious attacks