1,657 research outputs found
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
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A Static Verification Framework for Secure Peer-to-Peer Applications
In this paper we present a static verification framework to support the design and verification of secure peer-to-peer applications. The framework supports the specification, modeling, and analysis of security aspects together with the general characteristics of the system, during early stages of the development life-cycle. The approach avoids security issues to be taken into consideration as a separate layer that is added to the system as an afterthought by the use of security protocols. The main functionality supported by the framework are concerned with the modeling of the system together with its security aspects by using an extension of UML, modeling of abuse cases to represent scenarios of attackers and assist with the identification of properties to be verified, specification of properties to be verified in a graphical template language, verification of the models against the properties, and visualization of the results of the verification process
A Novel Blind Signature Scheme Based On Discrete Logarithm Problem With Un-traceability
Blind Signatures are a special type of digital signatures which possess two special properties of blindness and untraceability, which are important for today’s real world applications that require authentication , integrity , security , anonymity and privacy.
David Chaum[2] was the first to propose the concept of blind signatures. The scheme's security was based on the difficulty of solving the factoring problem [3, 4]. Two properties that are important for a blind signature scheme in order to be used in various modern applications are blindness and untraceability[2, 5, 6] . Blindness means that the signer is not able to know the contents of the message while signing it, which is achieved by disguising (or blinding) the message through various methods. Untraceability refers to preventing the signer from linking the blinded message it signs to a later unblinded version that it may be called upon to verify.
Blind signatures based on discrete logarithm problem are still an area with much scope for research. We aim to propose a novel blind signature scheme with untraceability , based on the discrete logarithm problem
A Covert Encryption Method for Applications in Electronic Data Interchange
A principal weakness of all encryption systems is that the output data can be ‘seen’ to be encrypted. In other words, encrypted data provides a ‘flag’ on the potential value of the information that has been encrypted. In this paper, we provide a new approach to ‘hiding’ encrypted data in a digital image.
In conventional (symmetric) encryption, the plaintext is usually represented as a binary stream and encrypted using an XOR type operation with a binary cipher. The algorithm used is ideally designed to: (i) generate a maximum entropy cipher so that there is no bias with regard to any bit; (ii) maximize diffusion in terms of key dependency so that a change in any bit of the key can effect any, and potentially all, bits of the cipher. In the work reported here, we consider an approach in which a binary or low-bit plaintext image is encrypted with a decimal integer or floating point cipher using a convolution operation and the output quantized into a 1-bit array generating a binary image ciphertext. This output is then ‘embedded’ in a host image to hide the encrypted information. Embedding is undertaken either in the lowest 1-bit layer or multiple 1-bit layers. Decryption is accomplished by: (i) extracting the binary image from the host image; (ii) correlating the result with the original cipher. In principle, any cipher generator can be used for this purpose and the method has been designed to operate with 24-bit colour images. The approach has a variety of applications and, in this paper, we focus on the authentication and self-authentication of e-documents (letters and certificates, for example) that are communicated over the Internet and are thereby vulnerable to attack (e.g. modification, editing, counterfeiting etc.). In addition to document authentication, the approach considered provides a way of propagating disinformation and a solution to scenarios that require ‘plausible deniability’
A novel group signature scheme without one way hash
The group signatures scheme was introduced by Chaum and van Heijst which allow members of a group to sign messages anonymously on behalf of the whole group. Only a
designated Group Manager is able to trace the identify of the group member who issued a valid signature. The group members sign a message with their secret key gsk and produce
a signature that cannot be linked to the identities of the signers without the secret key of the manager. The group manager can open the signature to recover the identities of the signers in case of any legal dispute. Group signatures have been widely used in Electronic markets where the sellers are the group members, the buyers are the veriers and the market administrator is the group manager.
We aim to propose a group signature scheme that is devoid of any one-way hash function and is based upon the Integer Factorization Problem (IFP). The scheme uses the concept
of safe primes to further enhance the security of the scheme. The scheme supports message recovery and hence the overload of sending the message is avoided. The scheme satisfies security properties such as Anonymity (The verier cannot link a signature to the identity
of the signer), Traceability (The Group Manager can trace the identity of the signer of any
valid signature), Unforgeability (A valid signature cannot be produced without the group
secret keys), Exculpability (Neither the GM nor any member can produce a signature on
behalf of a group member)
Zero-Knowledge Proof-of-Identity: Sybil-Resistant, Anonymous Authentication on Permissionless Blockchains and Incentive Compatible, Strictly Dominant Cryptocurrencies
Zero-Knowledge Proof-of-Identity from trusted public certificates (e.g.,
national identity cards and/or ePassports; eSIM) is introduced here to
permissionless blockchains in order to remove the inefficiencies of
Sybil-resistant mechanisms such as Proof-of-Work (i.e., high energy and
environmental costs) and Proof-of-Stake (i.e., capital hoarding and lower
transaction volume). The proposed solution effectively limits the number of
mining nodes a single individual would be able to run while keeping membership
open to everyone, circumventing the impossibility of full decentralization and
the blockchain scalability trilemma when instantiated on a blockchain with a
consensus protocol based on the cryptographic random selection of nodes.
Resistance to collusion is also considered.
Solving one of the most pressing problems in blockchains, a zk-PoI
cryptocurrency is proved to have the following advantageous properties:
- an incentive-compatible protocol for the issuing of cryptocurrency rewards
based on a unique Nash equilibrium
- strict domination of mining over all other PoW/PoS cryptocurrencies, thus
the zk-PoI cryptocurrency becoming the preferred choice by miners is proved to
be a Nash equilibrium and the Evolutionarily Stable Strategy
- PoW/PoS cryptocurrencies are condemned to pay the Price of Crypto-Anarchy,
redeemed by the optimal efficiency of zk-PoI as it implements the social
optimum
- the circulation of a zk-PoI cryptocurrency Pareto dominates other PoW/PoS
cryptocurrencies
- the network effects arising from the social networks inherent to national
identity cards and ePassports dominate PoW/PoS cryptocurrencies
- the lower costs of its infrastructure imply the existence of a unique
equilibrium where it dominates other forms of paymentComment: 2.1: Proof-of-Personhood Considered Harmful (and Illegal); 4.1.5:
Absence of Active Authentication; 4.2.6: Absence of Active Authentication;
4.2.7: Removing Single-Points of Failure; 4.3.2: Combining with
Non-Zero-Knowledge Authentication; 4.4: Circumventing the Impossibility of
Full Decentralizatio
Digital Image Watermarking Using LSB Method
Nowadays, the transmision of data is very important and it has been carried out by using digital media (Internet, e-mail). There are some problems that may occur in the transmission of digital media data which is associated with data security level to be sent. Base on that condition, the thought of doing data concealment are emerge. Digital image is one of the most common media used by the community. Digital watermarking is one of cryptography methods which used to hide data into digital image so that the data sent cannot be identified by the irresponsible people. Data encryption is used to improve the security of data to be sent. Internet as the world's largest network system that connects nearly all computer worlds, making all the c omputers in the world is increasingly easy to exchange data. There are so many digital data falsification has occurred. Digital falsification of data aimed to succeed the counterfeiting syndicate these hidden plans. the falsification problem of digital data will from be resolved by applying the watermarking using LSB method (Least Significant Bit)
Practical Unconditionally Secure Two-channel Message Authentication
We investigate unconditional security for message authentication protocols that are designed using two-channel cryptography. We look at both noninteractive message authentication protocols (NIMAPs) and interactive message authentication protocols (IMAPs). We provide a new proof of nonexistence of nontrivial unconditionally secure NIMAPs. This proof consists of a combinatorial counting argument and is much shorter than the previous proof by Wang et al., which was based on probability distribution arguments. Further, we propose a generalization of an unconditionally secure 3-round IMAP due to Naor, Segev and Smith. With a careful choice of parameters, our scheme improves that of Naor et al. Our scheme is very close to optimal for most parameter situations of practical interest.
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