Antigoni Polychroniadou

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Adaptively secure Multi-Party Computation (MPC) first studied by Canetti, Feige, Goldreich, and Naor in 1996, is a fundamental notion in cryptography. Adaptive security is particularly hard to achieve in settings where arbitrary number of parties can be corrupted and honest parties are not trusted to properly erase their internal state. We did not know how(More)
Usenix 2008-Halderman et al. noted that DRAMs retain their contents for a while after power is lost. Bits in memory can be extracted, but they will have errors. 0 bits will always flip with very low probability (<1%), but 1 bits will flip with much higher probability which increases with time. Why is this a problem? Secrets may be stored in memory. The Big(More)
We revisit the exact round complexity of secure computation in the multi-party and two-party settings. For the special case of two-parties without a simultaneous message exchange channel, this question has been extensively studied and resolved. In particular, Katz and Ostrovsky (CRYPTO '04) proved that five rounds are necessary and sucient for securely(More)
We present a universally composable multiparty computation protocol that is adap-tively secure against corruption of n − 1 of the n players. The protocol has a constant number of rounds and communication complexity that depends only on the number of inputs and outputs (and not on the size of the circuit to be computed securely). Such protocols were already(More)
Many information theoretically secure protocols are known for general secure multi-party computation, both in the honest majority setting, and in the dishonest majority setting with preprocessing. All known protocols that are efficient in the circuit size of the evaluated function follow the same typical " gate-by-gate " design pattern: we work our way(More)
Adaptively secure Multi-Party Computation (MPC) is an essential and fundamental notion in cryptography. In this work, we construct Universally Composable (UC) MPC protocols that are adaptively secure against all-but-one corruptions based on LWE. Our protocols have a constant number of rounds and communication complexity dependant only on the length of the(More)
We put forth a new formulation of tamper-proof hardware in the Global Universal Composable framework introduced by Canetti et al. in TCC 2007. In particular, this will allow reasoning about composable security by analyzing only a single instance of the protocol in isolation. Almost all of the previous works rely on the formulation by Katz in Eurocrypt 2007(More)
Secure computation in the presence of tamper-proof hardware tokens is proven under the assumption that the holder of the token is only given black-box access to the functionality of the token. Starting with the work of Goldreich and Ostrovsky [GO96], a long series of works studied tamper-proof hardware for realizing two-party functionalities in a variety of(More)