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)
Inspired by cold boot attacks, Heninger and Shacham (Crypto 2009) initiated the study of the problem of how to recover an RSA private key from a noisy version of that key. They gave an algorithm for the case where some bits of the private key are known with certainty. Their ideas were extended by Henecka, May and Meurer (Crypto 2010) to produce an algorithm(More)
We present a universally composable multiparty computation protocol that is adaptively 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)
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)
We revisit the exact round complexity of secure computation in the multi-party and twoparty 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 sufficient for securely(More)
Peptides were isolated from the water-soluble fraction of Feta cheese by reversed-phase HPLC in three successive steps. Peptide sequencing was performed by automatic Edman degradation. Most of the peptides originated from alpha s1-casein (CN), especially from the N-terminal half of the molecule. Two peptides originated from the C-terminal domain of beta-CN.(More)
A central problem in cryptography is that of converting protocols that offer security against passive (or semi-honest) adversaries into ones that offer security against active (or malicious) adversaries. This problem has been the topic of a large body of work in the area of secure multiparty computation (MPC). Despite these efforts, there are still big(More)
We put forth a new formulation of tamper-proof hardware in the Global Universal Composable (GUC) framework introduced by Canetti et al. in TCC 2007. Almost all of the previous works rely on the formulation by Katz in Eurocrypt 2007 and this formulation does not fully capture tokens in a concurrent setting. We address these shortcomings by relying on the GUC(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)