Scoring methods in multiple−choice tests are usually designed as fair bets, and thus random guesswork yields zero expected return. This causes the undesired result of forcing risk averse test−takers to pay a premium in the sense of letting unmarked answers for which they have partial but not full knowledge. In this note I use a calibrated model of prospect theory [Tversky and Kahneman (1992, 19...

We investigate the problem of guessing a random vector X within distortion level D. Our aim is to characterize the best attainable performance in the sense of minimizing, in some probabilistic sense, the number of required guesses G(X) until the error falls below D. The underlying motivation is that G(X) is the number of candidate codewords to be examined by a rate-distortion block encoder unti...

Hat problems have become a popular topic in recreational mathematics. In a typical hat problem, each of n players tries to guess the color of the hat they are wearing by looking at the colors of the hats worn by some of the other players. In this paper we consider several variants of the problem, united by the common theme that the guessing strategies are required to be deterministic and the ob...

Given d complex numbers z1, ..., zd, it is classical that linear dependencies λ1 z1+ ···+ λd zd=0 with λ1, ..., λd∈Z can be guessed using the LLL-algorithm. Similarly, given d formal power series f1, ..., fd ∈ C[[z]], algorithms for computing Padé-Hermite forms provide a way to guess relations P1 f1 + ···+ Pd fd = 0 with P1, ..., Pd ∈C[z]. Assuming that f1, ..., fd have a radius of convergence ...

Passwords still dominate the authentication space, but they are vulnerable to many different attacks; in recent years, guessing attacks in particular have notably caused a few high-profile information leaks. Password strength checkers, which attempt to guard against guessing attacks by enforcing heuristics like length and character variety, only model resistance to these brute-force attacks by ...

Text-based passwords, dominant mechanism of authentication nowadays, are vulnerable to malicious attackers. Even though not recommended, users tend to use personal information (PI) when create passwords. Only a few studies have researched targeted password guessing, in which attackers guess passwords by utilizing users’ PI. We propose TPGXNN, a framework that uses neural networks (NN) in target...

On 18 October 2006 the British tabloid newspaper the Daily Star carried the front page headline ‘BBC PUT MUSLIMS BEFORE YOU!’. The headline was accompanied by a picture of a woman in a face-covering niqab making a two-fingered gesture. Despite the fact that the 2001 census recorded 1,588,890 Muslims living in the United Kingdom, comprising 2.78 per cent of the population, the use of the word yo...