We study a model of fairness in secure computation in which an adversarial party that aborts
on receiving output is forced to pay a mutually predefined monetary penalty. We then show …

An aggregate signature scheme is a digital signature that supports aggregation: Given n
signatures on n distinct messages from n distinct users, it is possible to aggregate all these …

We introduce and construct timed commitment schemes, an extension to the standard notion
of commitments in which a potential forced opening phase permits the receiver to recover …

Secure multiparty computation allows mutually distrusting parties to compute a function on
their private inputs such that nothing but the function output is revealed. Achieving fairness …

Many cryptographic tasks and protocols, such as non-repudiation, contract-signing, voting,
auction, identity-based encryption, and certain forms of secure multi-party computation …

We introduce the concept of concurrent signatures. These allow two entities to produce two
signatures in such a way that, from the point of view of any third party, both signatures are …

We consider the problem of buying physical goods with cryptocurrencies. There is an
inherent circular dependency: should be the buyer trust the seller and pay before receiving …

The outsourcing computations in distributed environments suffer from the trust problems
between the outsourcer and the workers. All existing solutions only assume the rational lazy …

Security APIs, key servers and protocols that need to keep the status of transactions, require
to maintain a global, non-monotonic state, eg, in the form of a database or register. However …

The growing importance of electronic commerce and the increasing number of applications
in this area has led research into studying methods of how to perform safe and secure online …