All or Nothing at All

All or Nothing at All

We continue a study of unconditionally secure all-or-nothing transforms (AONT) begun in [12]. An AONT is a bijective mapping that constructs s outputs from s inputs. We consider the security of t inputs, when s − t outputs are known. Previous work concerned the case t = 1; here we consider the problem for general t, focussing on the case t = 2. We investigate constructions of binary matrices fo...

All-or-Nothing Monitoring

A principal can observe both the output and input of an agent who works at a job involving multiple tasks. We provide a simple theory that explains why it may be optimal for the principal to use only output-based incentive contract, even though the principal can monitor the agent’s actions perfectly in all but one task and knows exactly which action is optimal for each task. (JEL: D82, M5, J33)

Overwriting : All or Nothing ?

Hats: all or nothing

N distinguishable players are randomly fitted with a white or black hat, where the probabilities of getting a white or black hat may be different, but known and the same to all the players. All players guess simultaneously the color of their own hat observing only the hat colors of the other N − 1 players. The team wins if all players guess right. No communication of any sort is allowed, except...

Take-all or nothing

Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in Gaeumannomyces by combining morphology and multi-locus phylogenetic analyses based on partial gene sequences of I...