, protocols are guaranteed to maintain their security in any context, even in the presence of an unbounded number of arbitrary protocol instances that run concurrently in an adversarially controlled manner. This is a useful guarantee, that allows arguing about the security of cryptographic protocols

is the network capacity. In contrast, when the adversary has limited eavesdropping capabilities, we provide algorithms that achieve the higher rate of C − zO. Our algorithms attain the optimal rate given the strength of the adversary. They are informationtheoretically secure. They operate in a distributed manner

In this work we consider the communication of information in the presence of a causal adversarial jammer. In the setting under study, a sender wishes to communicate a message to a receiver by transmitting a codeword x = (x1,..., xn) bit-by-bit over a communication channel. The adversarial jammer

-line manner, and each party incrementally updates a compressed sketch of its input. The parties are not allowed to communicate, they do not share any secret information, and any public information they share is known to the adversary in advance. Then, the parties engage in a protocol in order to evaluate

In this work we consider the communication of information in the presence of an online adversarial jammer. In the setting under study, a sender wishes to communicate a message to a receiver by transmitting a codeword x = (x1,..., xn) symbol-by-symbol over a communication channel. The adversarial

be benign in isolation but might reveal more than a user is comfortable with in combination. Additionally malicious adversaries who wish to learn more than allowed might query in a manner that attempts to hide the flows of sensitive information. Finally, users cannot rely on

mechanism, as well as balanced node dispersal. These desired properties are maintained in a decentralized manner without resorting to global updates or periodic stabilization protocols even against an adaptive adversary that controls the arrival and departure of nodes. 1

A group of agents are said to collude if they share infor-mation or make joint decisions in a manner contrary to explicit or implicit social rules that results in an unfair advantage over non-colluding agents or other interested parties. For instance, collusion manifests as sharing an

-tampering adversaries. We prove that gate-tampering is strictly stronger than wire-tampering. On the one hand, we show that there is a gate-tampering strategy that perfectly simulates any given wire-tampering strategy. On the other, we construct families of circuits over which it is impossible for any wire

We introduce a model for electronic election schemes that involves a more powerful adversary than in previous work. In particular, we allow the adversary to demand of coerced voters that they vote in a particular manner, abstain from voting, or even disclose their secret keys. We define a scheme