Visual Cryptography-Based Secure QR Payment System Design and Implementation

It is important to validate the Merchant and the Client to increase confidence in online transactions. At present, only the Client is checked against the merchant server. The research in this paper will show you how to create and launch a QR code-based payment system that is both secure and convenient for users. As a result of their capacity to facilitate instantaneous transactions and offer unparalleled ease of use, QR codes have seen explosive growth in the past few years. QR-based online payment systems are easy to use but susceptible to various assaults. So, for the level of security given by transaction processing to hold, the secrecy and integrity of each payment procedure must be guaranteed. In addition, the online payment system must verify each transaction from both the sender's and the recipient's perspectives. The study's QR-based method is kept safe through visual cryptography. The suggested approach takes advantage of visual cryptography via a web-based application

Design of data validation solutions using high density 2D colored codes and a (2,2) xor-based color interference visual cryptography scheme

Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2018.A validação de dados nos sistemas de informação utiliza majoritariamente algoritmos criptográficos em sistemas que, geralmente, não utilizam materiais não eletrônicos como parte da infraestrutura do criptossistema. Nesse trabalho, foram desenvolvidos dois sistemas de armazenamento e recuperação de dados através da proposta de uma nova tecnologia de códigos de barra colorido bidimensional e de um novo esquema de criptografia visual. Os códigos de barras bidimensionais têm sido amplamente estudados, mas ainda continuam sem contar com um padrão que consiga transmitir alta quantidade de informação em pequenos espaços impressos. As aplicações desse modelo de transmissão tem como motivação a necessidade de armazenar (e recuperar) uma alta quantidade de informação em pequenas áreas impressas, como por exemplo, para utilização de dados criptográficos que sejam processados sem conexão e armazenados em pequenos espaços impressos, como os de caixas de remédios ou caixas de cigarros. O código de barras colorido 2D proposto nesse trabalho é chamado de High Density 2 Dimensional Code (HD2DC) e possui 8 diferentes tamanhos. O HD2DC permite a utilização de 5 ou 8 cores em cada tamanho e conta com o algoritmo de correção de erro Reed-Solomon com 3 diferentes níveis (10%, 20% e 30%). O HD2DC foi desenvolvido com o objetivo de ser um padrão de código de barras colorido 2D para operações de transmissão de grande quantidade de informações em pequenas ou médias áreas de impressão. Criptografia visual é uma técnica que cifra uma imagem secreta em duas ou mais imagens chave. A decodificação de qualquer esquema de criptografia visual depende do sistema visual humano e a maioria das propostas existentes consideram para a decodificação a utilização da sobreposição de duas ou mais lâminas físicas com n x n (n ≥ 2) pixels expandidos. O esquema de criptografia visual proposto nesse trabalho considera a utilização de duas imagens. A primeira é uma lâmina física feita por uma impressão colorida em Policloreto de Polivinila (PVC) transparente de 3 milímetros, enquanto que a segunda é uma imagem colorida apresentada na tela do visor de um smartphone. Ambas as imagens não geram expansão de pixels. A obtenção das melhores cores utilizadas nesse criptossistema foi realizada através de estudos físicos do comportamento da interferência de cor entre a tela do smartphone e a cor utilizada na impressão do PVC transparente. Essa nova proposta possui um alto nível de usabilidade para validação de dados em transações eletrônicas e conta com um custo muito baixo de implementação. Um sistema robusto de validação de dados é criado quando é combinada a criptografia visual proposta com o HD2DC. O HD2DC tem a capacidade de armazenar uma das imagens chave, no caso a que deve ser mostrada no visor do celular, essa arquitetura de codificação aumenta a percepção de segurança e explora a usabilidade do celular por meio da utilização da câmera e da tela como ferramentas para mostrar a imagem cifrada da criptografia visual.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Digital data validation generally requires that algorithms are ran into on cryptographic systems that, usually, do not use non-electronic devices as part of their information security infrastructure. This work presents two information storage and retrieval systems: a new colored two-dimensional barcode technology and a novel visual cryptography scheme. Two-dimensional barcodes have been a topic of research for several decades, but there is still no standard that stores and retrieves high amounts of data. Recently, new requirements have been imposed on applications that use 2D barcodes as a communication channel, such as the capability of storing information into a small printed area. This particular requirement is specially important for 2D barcodes that store cryptographic primitives to be processed off-line. This is the case of barcodes in products like cigarettes and medicines, which are used for data validation and product verification. The proposed 2D colored barcode is called High Density Two-Dimensional Code (HD2DC) and is currently one of the 2D barcodes with the highest data density. HD2DC can be generated in 8 different sizes, with 5 or 8 colors. To increase robustness, the system uses a Reed-Solomon error correction algorithm with 3 different levels: Low, Medium and High, which provide approximately 10%, 20% and 30% error correction, respectively. Visual cryptography (VC) is a technique that encodes the content of a secret image into two or more images, which are called shares. These shares are printed on transparencies and superimposed (requiring a good alignment) to reveal (visually) the original secret image, i.e. without requiring any computation. Current visual cryptography schemes use at least 2 shares (transparencies) as keys. With respect to the secret image size, most of these schemes produce a n x n (n ≥ 2) size expansion of the shares and the decoded image. The proposed Visual Cryptography scheme, on the other hand, uses two shares and does not require a size expansion. The first share is a colored film printed on a Polyvinyl Chloride (PVC) surface of 3 millimeters, while the second share is a colored image displayed on a smartphone or tablet. In this work, we performed a physical evaluation of the color interference properties of these two shares (the printed PVC transparency and the image displayed on the mobile device) to find the most adequate color space to be used in the proposed cryptosystem. We also propose a strong validation system combining our Xor-Based Visual Cryptography scheme with HD2DC. HD2DC has the capability of storing the share that is shown on the mobile device display. This encoding architecture enhances security perception and explores the mobile device usability, using its screen to display a Visual Cryptography share

Ubic: Bridging the gap between digital cryptography and the physical world

Advances in computing technology increasingly blur the boundary between the digital domain and the physical world. Although the research community has developed a large number of cryptographic primitives and has demonstrated their usability in all-digital communication, many of them have not yet made their way into the real world due to usability aspects. We aim to make another step towards a tighter integration of digital cryptography into real world interactions. We describe Ubic, a framework that allows users to bridge the gap between digital cryptography and the physical world. Ubic relies on head-mounted displays, like Google Glass, resource-friendly computer vision techniques as well as mathematically sound cryptographic primitives to provide users with better security and privacy guarantees. The framework covers key cryptographic primitives, such as secure identification, document verification using a novel secure physical document format, as well as content hiding. To make a contribution of practical value, we focused on making Ubic as simple, easily deployable, and user friendly as possible.Comment: In ESORICS 2014, volume 8712 of Lecture Notes in Computer Science, pp. 56-75, Wroclaw, Poland, September 7-11, 2014. Springer, Berlin, German

Secure digital documents using Steganography and QR Code

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University LondonWith the increasing use of the Internet several problems have arisen regarding the processing of electronic documents. These include content filtering, content retrieval/search. Moreover, document security has taken a centre stage including copyright protection, broadcast monitoring etc. There is an acute need of an effective tool which can find the identity, location and the time when the document was created so that it can be determined whether or not the contents of the document were tampered with after creation. Owing the sensitivity of the large amounts of data which is processed on a daily basis, verifying the authenticity and integrity of a document is more important now than it ever was. Unsurprisingly document authenticity verification has become the centre of attention in the world of research. Consequently, this research is concerned with creating a tool which deals with the above problem. This research proposes the use of a Quick Response Code as a message carrier for Text Key-print. The Text Key-print is a novel method which employs the basic element of the language (i.e. Characters of the alphabet) in order to achieve authenticity of electronic documents through the transformation of its physical structure into a logical structured relationship. The resultant dimensional matrix is then converted into a binary stream and encapsulated with a serial number or URL inside a Quick response Code (QR code) to form a digital fingerprint mark. For hiding a QR code, two image steganography techniques were developed based upon the spatial and the transform domains. In the spatial domain, three methods were proposed and implemented based on the least significant bit insertion technique and the use of pseudorandom number generator to scatter the message into a set of arbitrary pixels. These methods utilise the three colour channels in the images based on the RGB model based in order to embed one, two or three bits per the eight bit channel which results in three different hiding capacities. The second technique is an adaptive approach in transforming domain where a threshold value is calculated under a predefined location for embedding in order to identify the embedding strength of the embedding technique. The quality of the generated stego images was evaluated using both objective (PSNR) and Subjective (DSCQS) methods to ensure the reliability of our proposed methods. The experimental results revealed that PSNR is not a strong indicator of the perceived stego image quality, but not a bad interpreter also of the actual quality of stego images. Since the visual difference between the cover and the stego image must be absolutely imperceptible to the human visual system, it was logically convenient to ask human observers with different qualifications and experience in the field of image processing to evaluate the perceived quality of the cover and the stego image. Thus, the subjective responses were analysed using statistical measurements to describe the distribution of the scores given by the assessors. Thus, the proposed scheme presents an alternative approach to protect digital documents rather than the traditional techniques of digital signature and watermarking

Printed document integrity verification using barcode

Printed documents are still relevant in our daily life and information in it must be protected from threats and attacks such as forgery, falsification or unauthorized modification. Such threats make the document lose its integrity and authenticity. There are several techniques that have been proposed and used to ensure authenticity and originality of printed documents. But some of the techniques are not suitable for public use due to its complexity, hard to obtain special materials to secure the document and expensive. This paper discuss several techniques for printed document security such as watermarking and barcode as well as the usability of two dimensional barcode in document authentication and data compression with the barcode. A conceptual solution that are simple and efficient to secure the integrity and document sender's authenticity is proposed that uses two dimensional barcode to carry integrity and authenticity information in the document. The information stored in the barcode contains digital signature that provides sender's authenticity and hash value that can ensure the integrity of the printed document

SBVLC:Secure Barcode-based Visible Light Communication for Smartphones

2D barcodes have enjoyed a significant penetration rate in mobile applications. This is largely due to the extremely low barrier to adoption – almost every camera-enabled smartphone can scan 2D barcodes. As an alternative to NFC technology, 2D barcodes have been increasingly used for security-sensitive mobile applications including mobile payments and personal identification. However, the security of barcode-based communication in mobile applications has not been systematically studied. Due to the visual nature, 2D barcodes are subject to eavesdropping when they are displayed on the smartphone screens. On the other hand, the fundamental design principles of 2D barcodes make it difficult to add security features. In this paper, we propose SBVLC - a secure system for barcode-based visible light communication (VLC) between smartphones. We formally analyze the security of SBVLC based on geometric models and propose physical security enhancement mechanisms for barcode communication by manipulating screen view angles and leveraging user-induced motions. We then develop three secure data exchange schemes that encode information in barcode streams. These schemes are useful in many security-sensitive mobile applications including private information sharing, secure device pairing, and contactless payment. SBVLC is evaluated through extensive experiments on both Android and iOS smartphones