Visual Cryptographic Protocols Using the Trusted Initializer

2005 ◽  
pp. 112-122 ◽  
Author(s):  
Hidenori Kuwakado ◽  
Masakatu Morii ◽  
Hatsukazu Tanaka
Keyword(s):  
Cryptographic Protocols

Security Analysis of Wireless Authentication Protocols

2019 ◽  
Vol 9 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Ashish Joshi ◽  
Amar Kumar Mohapatra
Keyword(s):  
Execution Time ◽  
Communication Systems ◽  
Security Analysis ◽  
Cryptographic Protocols ◽  
Command Line ◽  
Time Analysis ◽  
Authentication Protocols ◽  
Replay Attack ◽  
Peer Communication ◽  
Digital Communication Systems

Background & Objective: Cryptographic protocols had been evident method for ensuring con dentiality, Integrity and authentication in various digital communication systems. However the validation and analysis of such cryptographic protocols was limited to usage of formal mathematical models until few years back. Methods: In this paper, various popular cryptographic protocols have been studied. Some of these protocols (PAP, CHAP, and EAP) achieve security goals in peer to peer communication while others (RADIUS, DIAMETER and Kerberos) can work in multiparty environment. These protocols were validated and analysed over two popular security validation and analysis tools AVISPA and Scyther. The protocols were written according to their documentation using the HLPSL and SPDL for analysis over AVISPA and Scyther respectively. The results of these tools were analysed to nd the possible attack an each protocol. Afterwards The execution time analysis of the protocols were done by repeating the experiment for multiple iterations over the command line versions of these tools.As the literature review suggested, this research also validates that using password based protocols (PAP) is faster in terms of execution time as compared to other methods, Usage of nonces tackles the replay attack and DIAMETER is secure than RADIUS. Results and Conclusion: The results also showed us that DIAMETER is faster than RADIUS. Though Kerberos protocol was found to safe, the results tell us that it is compromisable under particular circumstances.

scholarly journals Computing conditional entropies for quantum correlations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peter Brown ◽  
Hamza Fawzi ◽  
Omar Fawzi
Keyword(s):  
Quantum Key Distribution ◽  
Detection Efficiency ◽  
Conditional Entropy ◽  
Key Distribution ◽  
Quantum Correlations ◽  
Upper Bounds ◽  
Cryptographic Protocols ◽  
Quantum States ◽  
Security Proofs

AbstractThe rates of quantum cryptographic protocols are usually expressed in terms of a conditional entropy minimized over a certain set of quantum states. In particular, in the device-independent setting, the minimization is over all the quantum states jointly held by the adversary and the parties that are consistent with the statistics that are seen by the parties. Here, we introduce a method to approximate such entropic quantities. Applied to the setting of device-independent randomness generation and quantum key distribution, we obtain improvements on protocol rates in various settings. In particular, we find new upper bounds on the minimal global detection efficiency required to perform device-independent quantum key distribution without additional preprocessing. Furthermore, we show that our construction can be readily combined with the entropy accumulation theorem in order to establish full finite-key security proofs for these protocols.

scholarly journals New Statistical Randomness Tests Based on Length of Runs

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Ali Doğanaksoy ◽  
Fatih Sulak ◽  
Muhiddin Uğuz ◽  
Okan Şeker ◽  
Ziya Akcengiz
Keyword(s):  
Statistical Tests ◽  
Random Sequence ◽  
Cryptographic Protocols ◽  
Experimental Results ◽  
Security Evaluation ◽  
Random Numbers ◽  
Statistical Distributions ◽  
Cryptographic Algorithm ◽  
Encryption Algorithms ◽  
Randomness Tests

Random sequences and random numbers constitute a necessary part of cryptography. Many cryptographic protocols depend on random values. Randomness is measured by statistical tests and hence security evaluation of a cryptographic algorithm deeply depends on statistical randomness tests. In this work we focus on statistical distributions of runs of lengths one, two, and three. Using these distributions we state three new statistical randomness tests. New tests useχ2distribution and, therefore, exact values of probabilities are needed. Probabilities associated runs of lengths one, two, and three are stated. Corresponding probabilities are divided into five subintervals of equal probabilities. Accordingly, three new statistical tests are defined and pseudocodes for these new statistical tests are given. New statistical tests are designed to detect the deviations in the number of runs of various lengths from a random sequence. Together with some other statistical tests, we analyse our tests’ results on outputs of well-known encryption algorithms and on binary expansions ofe,π, and2. Experimental results show the performance and sensitivity of our tests.

REMARKS ON A QUERY-BASED VARIANT OF THE PARALLEL REPETITION THEOREM

2001 ◽  
Vol 12 (04) ◽  
pp. 517-531
Author(s):  
OLEG VERBITSKY
Keyword(s):  
Strong Correlation ◽  
Error Probability ◽  
Cryptographic Protocols ◽  
Parallel Execution ◽  
Proof System ◽  
Interactive Proof ◽  
Parallel Repetition ◽  
Interactive Proof System

The Parallel Repetition Theorem says that n-fold parallel execution of a two-prover one-round interactive proof system reduces the error probability exponentially in n. The bound on the error probability of the parallelized system depends on the error probability and the answer size of the single proof system. It is still unknown whether the theorem holds true with a bound depending only on the query size. This kind of a bound may be preferable whenever the query size is considerably smaller than the answer size, what really happens in some cryptographic protocols. Such a bound is only known in the case that queries to the provers are independent. The present paper extends this result to some cases of strong correlation between queries. In particular, a query-based variant of the Parallel Repetition Theorem is proven when the graph of dependence between queries to the provers is a tree and, in a bit weaker form, when this graph is a cycle.

Cryptographic Protocols Underlying Privacy-ABCs

2014 ◽  
pp. 79-108
Author(s):  
Patrik Bichsel ◽  
Jan Camenisch ◽  
Maria Dubovitskaya ◽  
Robert R. Enderlein ◽  
Stephan Krenn ◽  
...  
Keyword(s):  
Cryptographic Protocols
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