Corpus ID: 5033043

@article{Blocki2014HumanCP,
author={Jeremiah Blocki and Manuel Blum and Anupam Datta},
journal={ArXiv},
year={2014},
volume={abs/1404.0024}
}
• Published 2014
• Computer Science, Mathematics
• ArXiv
An interesting challenge for the cryptography community is to design authentication protocols that are so simple that a human can execute them without relying on a fully trusted computer. We propose several candidate authentication protocols for a setting in which the human user can only receive assistance from a semi-trusted computer --- a computer that stores information and performs computations correctly but does not provide confidentiality. Our schemes use a semi-trusted computer to store… Expand
12 Citations
• Computer Science, Mathematics
• ITCS
• 2017
The general hypercontractivity theorem is applied to lower bound the statistical dimension of the distribution over challenge-response pairs induced by f and $\sigma$, and lower bounds apply to arbitrary functions $f$ (not just to functions that are easy for a human to evaluate). Expand
Human-Usable Password Schemas: Beyond Information-Theoretic Security
• Computer Science
• ArXiv
• 2019
It is proved for several specific schemas that a computer is no worse off than an infinite adversary and that it can successfully extract all information from leaked challenges and their respective responses, known as challenge-response pairs. Expand
Usable Human Authentication: A Quantitative Treatment
The thesis is that user models and security models can guide the development of password management schemes with analyzable usability and security properties and introduces Naturally Rehearsing Password schemes and Human Computable Password schemes, which leverage human capabilities for simple arithmetic operations. Expand
On the Economics of Offline Password Cracking
• Computer Science
• 2018 IEEE Symposium on Security and Privacy (SP)
• 2018
It is advocated that password hashing standards should be updated to require the use of memory hard functions for password hashing and disallow the useof non-memory hard functions such as BCRYPT or PBKDF2. Expand
When are identification protocols with sparse challenges safe? The case of the Coskun and Herley attack
• Computer Science
• IACR Cryptol. ePrint Arch.
• 2015
An analytical estimate of the number of challenge-response pairs required by an eavesdropper to find the secret through the Coskun and Herley attack is shown, to help protocol designers to choose safe parameter sizes for identification protocols that employ sparse challenges. Expand
Human Computable Passwords - Design and Analysis.
The conclusion from the experiment was that failure rates are indeed an important usability factor which should be investigated more thoroughly, as it may limit the scheme severely. Expand
• Computer Science
• 2019 IEEE/CIC International Conference on Communications in China (ICCC)
• 2019
This work presents a neural network-based attack model, which consists of a feature extraction model and a prediction model, and proposes a risk alert system based on the attack model that can issue a timely warning notice when the password in use is at high security risk. Expand
On the Security and Usability of Segment-based Visual Cryptographic Authentication Protocols
• Computer Science
• CCS
• 2016
This work studies the security and usability of segment-based visual cryptographic authentication protocols (SVAPs), which include PassWindow as a special case, and finds that the protocol that offers the best security has the poorest usability. Expand
Making Code Voting Secure Against Insider Threats Using Unconditionally Secure MIX Schemes and Human PSMT Protocols
• Computer Science
• VoteID
• 2015
An unconditionally secure MIX based on the combinatorics of set systems is introduced, using PSMT protocols SCN 2012 where with the help of visual aids, humans can carry out mod10 addition correctly with a 99i¾?% degree of accuracy. Expand
• Computer Science
• HCOMP
• 2018
This work presents the first usability study of humanly computable password strategies, involving a learning phase (to learn a password strategy), then a rehearsal phase, then a login to a few websites, and multiple follow-up tests. Expand

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