## CryptoDB

### Ivan Damgård

#### Publications

Year
Venue
Title
2022
CRYPTO
Recently, number-theoretic assumptions including DDH, DCR and QR have been used to build powerful tools for secure computation, in the form of homomorphic secret-sharing (HSS), which leads to secure two-party computation protocols with succinct communication, and pseudorandom correlation functions (PCFs), which allow non-interactive generation of a large quantity of correlated randomness. In this work, we present a group-theoretic framework for these classes of constructions, which unifies their approach to computing distributed discrete logarithms in various groups. We cast existing constructions in our framework, and also present new constructions, including one based on class groups of imaginary quadratic fields. This leads to the first construction of two-party homomorphic secret sharing for branching programs from class group assumptions. Using our framework, we also obtain pseudorandom correlation functions for generating oblivious transfer and vector-OLE correlations from number-theoretic assumptions. These have a trustless, public-key setup when instantiating our framework using class groups. Previously, such constructions either needed a trusted setup in the form of an RSA modulus with unknown factorisation, or relied on multi-key fully homomorphic encryption from the learning with errors assumption. We also show how to upgrade our constructions to achieve active security using appropriate zero-knowledge proofs. In the random oracle model, this leads to a one-round, actively secure protocol for setting up the PCF, as well as a 3-round, actively secure HSS-based protocol for secure two-party computation of branching programs with succinct communication.
2022
TCC
Compressed $\Sigma$-Protocol Theory (CRYPTO 2020) presents an alternative'' to Bulletproofs that achieves the same communication complexity while adhering more elegantly to existing $\Sigma$-protocol theory, which enables their techniques to be directly applicable to other widely used settings in the context of plug \& play'' algorithmics. Unfortunately, their techniques are restricted to arithmetic circuits over \emph{prime} fields, which rules out the possibility of using more machine-friendly moduli such as powers of $2$, which have proven to improve efficiency in applications. In this work we show that such techniques can be generalized to the case of arithmetic circuits modulo \emph{any} number. This enables the use of powers of $2$, which can prove to be beneficial for efficiency, but it also facilitates the use of other moduli that might prove useful in different applications. In order to achieve this, we first present an instantiation of the main building block of the theory of compressed $\Sigma$-protocols, namely compact vector commitments. Our construction, which may be of independent interest, is homomorphic modulo \emph{any} positive integer $m$, a result that was not known in the literature before. Second, we generalize Compressed $\Sigma$-Protocol Theory from finite fields to $\mathbb{Z}_m$. The main challenge here is ensuring that there are large enough challenge sets as to fulfill the necessary soundness requirements, which is achieved by considering certain ring extensions. Our techniques have direct application for example to verifiable computation on homomorphically encrypted data.
2021
PKC
Although they have been studied for a long time, distributed signature protocols have garnered renewed interest in recent years in view of novel applications to topics like blockchains. Most recent works have focused on distributed versions of ECDSA or variants of Schnorr signatures, however, and in particular, little attention has been given to constructions based on post-quantum secure assumptions like the hardness of lattice problems. A few lattice-based threshold signature and multi-signature schemes have been proposed in the literature, but they either rely on hash-and-sign lattice signatures (which tend to be comparatively inefficient), use expensive generic transformations, or only come with incomplete security proofs. In this paper, we construct several lattice-based distributed signing protocols with low round complexity following the Fiat--Shamir with Aborts (FSwA) paradigm of Lyubashevsky (Asiacrypt 2009). Our protocols can be seen as distributed variants of the fast Dilithium-G signature scheme and the full security proof can be made assuming the hardness of module SIS and LWE problems. A key step to achieving security (unexplained in some earlier papers) is to prevent the leakage that can occur when parties abort after their first message---which can inevitably happen in the Fiat--Shamir with Aborts setting. We manage to do so using homomorphic commitments. Exploiting the similarities between FSwA and Schnorr-style signatures, our approach makes the most of observations from recent advancements in the discrete log setting, such as Drijvers et al.'s seminal work on two-round multi-signatures (S&P 2019). In particular, we observe that the use of commitment not only resolves the subtle issue with aborts, but also makes it possible to realize secure two-round n-out-of-n distributed signing and multi-signature in the plain public key model, by equipping the commitment with a trapdoor feature. The construction of suitable trapdoor commitment from lattices is a side contribution of this paper.
2021
CRYPTO
This paper closes the question of the possibility of two-round MPC protocols achieving different security guarantees with and without the availability of broadcast in any given round. Cohen et al. (Eurocrypt 2020) study this question in the dishonest majority setting; we complete the picture by studying the honest majority setting. In the honest majority setting, given broadcast in both rounds, it is known that the strongest guarantee — guaranteed output delivery — is achievable (Gordon et al. Crypto 2015). We show that, given broadcast in the first round only, guaranteed output delivery is still achievable. Given broadcast in the second round only, we give a new construction that achieves identifiable abort, and we show that fairness — and thus guaranteed output delivery — are not achievable in this setting. Finally, if only peer-to-peer channels are available, we show that the weakest guarantee — selective abort — is the only one achievable for corruption thresholds t > 1 and for t = 1 and n = 3. On the other hand, it is already known that selective abort can be achieved in these cases. In the remaining cases, i.e., t = 1 and n > 3, it is known (from the work of Ishai et al. at Crypto 2010, and Ishai et al. at Crypto 2015) that guaranteed output delivery (and thus all weaker guarantees) are possible.
2021
ASIACRYPT
In 2016, Guruswami and Wootters showed Shamir's secret-sharing scheme defined over an extension field has a regenerating property. Namely, we can compress each share to an element of the base field by applying a linear form, such that the secret is determined by a linear combination of the compressed shares. Immediately it seemed like an application to improve the complexity of unconditionally secure multiparty computation must be imminent; however, thus far, no result has been published. We present the first application of regenerating codes to MPC, and show that its utility lies in reducing the number of rounds. Concretely, we present a protocol that obliviously evaluates a depth-$d$ arithmetic circuit in $d + O(1)$ rounds, in the amortized setting of parallel evaluations, with $o(n^2)$ ring elements communicated per multiplication. Our protocol makes use of function-dependent preprocessing, and is secure against the maximal adversary corrupting $t < n/2$ parties. All existing approaches in this setting have complexity $\Omega(n^2)$. Moreover, we extend some of the theory on regenerating codes to Galois rings. It was already known that the repair property of MDS codes over fields can be fully characterized in terms of its dual code. We show this characterization extends to linear codes over Galois rings, and use it to show the result of Guruswami and Wootters also holds true for Shamir's scheme over Galois rings.
2021
TCC
In this work we consider information-theoretically secure MPC against an \emph{mixed} adversary who can corrupt $t_p$ parties passively, $t_a$ parties actively, and can make $t_f$ parties fail-stop. With perfect security, it is known that every function can be computed securely if and only if $3t_a + 2t_p + t_f < n$, for statistical security the bound is $2t_a + 2t_p + t_f < n$. These results say that for each given set of parameters $(t_a, t_p, t_f)$ respecting the inequality, there exists a protocol secure against this particular choice of corruption thresholds. In this work we consider a \emph{dynamic} adversary. Here, the goal is a \emph{single} protocol that is secure, no matter which set of corruption thresholds $(t_a, t_p, t_f)$ from a certain class is chosen by the adversary. A dynamic adversary can choose a corruption strategy after seeing the protocol and so is much stronger than a standard adversary. Dynamically secure protocols have been considered before for computational security. Also the information theoretic case has been studied, but only considering non-threshold adversaries, leading to inefficient protocols. We consider threshold dynamic adversaries and information theoretic security. For statistical security we show that efficient dynamic secure function evaluation (SFE) is possible if and only if $2t_a + 2t_p + t_f < n$, but any dynamically secure protocol must use $\Omega(n)$ rounds, even if only fairness is required. Further, general reactive MPC is possible if we assume in addition that $2t_a+2t_f \leq n$, but fair reactive MPC only requires $2t_a + 2t_p + t_f < n$. For perfect security we show that both dynamic SFE and verifiable secret sharing (VSS) are impossible if we only assume $3t_a + 2t_p + t_f < n$ and remain impossible even if we also assume $t_f=0$. In fact even SFE with security with abort is impossible in this case. On the other hand, perfect dynamic SFE with guaranteed output delivery (G.O.D.) is possible when either $t_p = 0$ or $t_a = 0$ i.e. if instead we assume $3t_a+t_f < n$ or $2t_p +t_f < n$. Further, perfect dynamic VSS with G.O.D. is possible under the stronger conditions $3t_a + 3/2t_f \leq n$ or $2t_p + 2t_f \leq n$. These conditions are also sufficient for perfect reactive MPC. On the other hand, because perfect fair VSS only requires $3t_a+2t_p+t_f< n$, perfect reactive MPC is possible whenever perfect SFE is.
2020
CRYPTO
In the context of secure computation, protocols with security against covert adversaries ensure that any misbehavior by malicious parties will be detected by the honest parties with some constant probability. As such, these protocols provide better security guarantees than passively secure protocols and, moreover, are easier to construct than protocols with full security against active adversaries. Protocols that, upon detecting a cheating attempt, allow the honest parties to compute a certificate that enables third parties to verify whether an accused party misbehaved or not are called publicly verifiable. In this work, we present the first generic compilers for constructing two-party protocols with covert security and public verifiability from protocols with passive security. We present two separate compilers, which are both fully blackbox in the underlying protocols they use. Both of them only incur a constant multiplicative factor in terms of bandwidth overhead and a constant additive factor in terms of round complexity on top of the passively secure protocols they use. The first compiler applies to all two-party protocols that have no private inputs. This class of protocols covers the important class of preprocessing protocols that are used to setup correlated randomness among parties. We use our compiler to obtain the first secret-sharing based two-party protocol with covert security and public verifiability. Notably, the produced protocol achieves public verifiability essentially for free when compared with the best known previous solutions based on secret-sharing that did not provide public verifiability Our second compiler constructs protocols with covert security and public verifiability for arbitrary functionalities from passively secure protocols. It uses our first compiler to perform a setup phase, which is independent of the parties' inputs as well as the protocol they would like to execute. Finally, we show how to extend our techniques to obtain multiparty computation protocols with covert security and public verifiability against arbitrary constant fractions of corruptions.
2020
TCC
Off-the-Record (OTR) messaging is a two-party message authentication protocol that also provides plausible deniability: there is no record that can later convince a third party what messages were actually sent. The challenge in group OTR, is to enable the sender to sign his messages so that group members can verify who sent a message (signatures should be unforgeable, even by group members). Also, we want the off-the-record property: even if some verifiers are corrupt and collude, they should not be able to prove the authenticity of a message to any outsider. Finally, we need consistency, meaning that if any group member accepts a signature, then all of them do. To achieve these properties it is natural to consider Multi-Designated Verifier Signatures (MDVS). However, existing literature defines and builds only limited notions of MDVS, where (a) the off-the-record property (source hiding) only holds when all verifiers could conceivably collude, and (b) the consistency property is not considered. The contributions of this paper are two-fold: stronger definitions for MDVS, and new constructions meeting those definitions. We strengthen source-hiding to support any subset of corrupt verifiers, and give the first formal definition of consistency. We build three new MDVS: one from generic standard primitives (PRF, key agreement, NIZK), one with concrete efficiency and one from functional encryption.
2020
ASIACRYPT
We study information-theoretic multiparty computation (MPC) protocols over rings Z/p^k Z that have good asymptotic communication complexity for a large number of players. An important ingredient for such protocols is arithmetic secret sharing, i.e., linear secret-sharing schemes with multiplicative properties. The standard way to obtain these over fields is with a family of linear codes C, such that C, $C^\perp$ and C^2 are asymptotically good (strongly multiplicative). For our purposes here it suffices if the square code C^2 is not the whole space, i.e., has codimension at least 1 (multiplicative). Our approach is to lift such a family of codes defined over a finite field F to a Galois ring, which is a local ring that has F as its residue field and that contains Z/p^k Z as a subring, and thus enables arithmetic that is compatible with both structures. Although arbitrary lifts preserve the distance and dual distance of a code, as we demonstrate with a counterexample, the multiplicative property is not preserved. We work around this issue by showing a dedicated lift that preserves \emph{self-orthogonality} (as well as distance and dual distance), for p > 2. Self-orthogonal codes are multiplicative, therefore we can use existing results of asymptotically good self-dual codes over fields to obtain arithmetic secret sharing over Galois rings. For p = 2 we obtain multiplicativity by using existing techniques of secret-sharing using both C and $C^\perp$, incurring a constant overhead. As a result, we obtain asymptotically good arithmetic secret-sharing schemes over Galois rings. With these schemes in hand, we extend existing field-based MPC protocols to obtain MPC over Z/p^k Z, in the setting of a submaximal adversary corrupting less than a fraction 1/2 - \varepsilon of the players, where \varepsilon > 0 is arbitrarily small. We consider 3 different corruption models, and obtain O(n) bits communicated per multiplication for both passive security and active security with abort. For full security with guaranteed output delivery we use a preprocessing model and get O(n) bits per multiplication in the online phase and O(n log n) bits per multiplication in the offline phase. Thus, we obtain true linear bit complexities, without the common assumption that the ring size depends on the number of players.
2019
CRYPTO
In this paper we provide a formal treatment of proof of replicated storage, a novel cryptographic primitive recently proposed in the context of a novel cryptocurrency, namely Filecoin.In a nutshell, proofs of replicated storage is a solution to the following problem: A user stores a file m on n different servers to ensure that the file will be available even if some of the servers fail. Using proof of retrievability, the user could check that every server is indeed storing the file. However, what if the servers collude and, in order to save on resources, decide to only store one copy of the file? A proof of replicated storage guarantees that, unless the (potentially colluding) servers are indeed reserving the space necessary to store n copies of the file, the user will not accept the proofs. While some candidate proofs of replicated storage have already been proposed, their soundness relies on timing assumptions i.e., the user must reject the proof if the prover does not reply within a certain time-bound.In this paper we provide the first construction of a proof of replication which does not rely on any timing assumptions.
2019
CRYPTO
We prove a lower bound on the communication complexity of unconditionally secure multiparty computation, both in the standard model with $n=2t+1$ parties of which t are corrupted, and in the preprocessing model with $n=t+1$ . In both cases, we show that for any $g \in \mathbb {N}$ there exists a Boolean circuit C with g gates, where any secure protocol implementing C must communicate $\varOmega (n g)$ bits, even if only passive and statistical security is required. The results easily extends to constructing similar circuits over any fixed finite field. This shows that for all sizes of circuits, the O(n) overhead of all known protocols when t is maximal is inherent. It also shows that security comes at a price: the circuit we consider could namely be computed among n parties with communication only O(g) bits if no security was required. Our results extend to the case where the threshold t is suboptimal. For the honest majority case, this shows that the known optimizations via packed secret-sharing can only be obtained if one accepts that the threshold is $t= (1/2 - c)n$ for a constant c. For the honest majority case, we also show an upper bound that matches the lower bound up to a constant factor (existing upper bounds are a factor $\lg n$ off for Boolean circuits).
2019
CRYPTO
In this work we present a collection of compilers that take secret sharing schemes for an arbitrary access structure as input and produce either leakage-resilient or non-malleable secret sharing schemes for the same access structure. A leakage-resilient secret sharing scheme hides the secret from an adversary, who has access to an unqualified set of shares, even if the adversary additionally obtains some size-bounded leakage from all other secret shares. A non-malleable secret sharing scheme guarantees that a secret that is reconstructed from a set of tampered shares is either equal to the original secret or completely unrelated. To the best of our knowledge we present the first generic compiler for leakage-resilient secret sharing for general access structures. In the case of non-malleable secret sharing, we strengthen previous definitions, provide separations between them, and construct a non-malleable secret sharing scheme for general access structures that fulfills the strongest definition with respect to independent share tampering functions. More precisely, our scheme is secure against concurrent tampering: The adversary is allowed to (non-adaptively) tamper the shares multiple times, and in each tampering attempt can freely choose the qualified set of shares to be used by the reconstruction algorithm to reconstruct the tampered secret. This is a strong analogue of the multiple-tampering setting for split-state non-malleable codes and extractors.We show how to use leakage-resilient and non-malleable secret sharing schemes to construct leakage-resilient and non-malleable threshold signatures. Classical threshold signatures allow to distribute the secret key of a signature scheme among a set of parties, such that certain qualified subsets can sign messages. We construct threshold signature schemes that remain secure even if an adversary leaks from or tampers with all secret shares.
2019
TCC
At CRYPTO 2018, Cramer et al. introduced a secret-sharing based protocol called SPD$\mathbb {Z}_{2^k}$ that allows for secure multiparty computation (MPC) in the dishonest majority setting over the ring of integers modulo $2^k$, thus solving a long-standing open question in MPC about secure computation over rings in this setting. In this paper we study this problem in the information-theoretic scenario. More specifically, we ask the following question: Can we obtain information-theoretic MPC protocols that work over rings with comparable efficiency to corresponding protocols over fields? We answer this question in the affirmative by presenting an efficient protocol for robust Secure Multiparty Computation over $\mathbb {Z}/p^{k}\mathbb {Z}$ (for any prime p and positive integer k) that is perfectly secure against active adversaries corrupting a fraction of at most 1/3 players, and a robust protocol that is statistically secure against an active adversary corrupting a fraction of at most 1/2 players.
2019
ASIACRYPT
Homomorphic universally composable (UC) commitments allow for the sender to reveal the result of additions and multiplications of values contained in commitments without revealing the values themselves while assuring the receiver of the correctness of such computation on committed values. In this work, we construct essentially optimal additively homomorphic UC commitments from any (not necessarily UC or homomorphic) extractable commitment, while the previous best constructions require oblivious transfer. We obtain amortized linear computational complexity in the length of the input messages and rate 1. Next, we show how to extend our scheme to also obtain multiplicative homomorphism at the cost of asymptotic optimality but retaining low concrete complexity for practical parameters. Moreover, our techniques yield public coin protocols, which are compatible with the Fiat-Shamir heuristic. These results come at the cost of realizing a restricted version of the homomorphic commitment functionality where the sender is allowed to perform any number of commitments and operations on committed messages but is only allowed to perform a single batch opening of a number of commitments. Although this functionality seems restrictive, we show that it can be used as a building block for more efficient instantiations of recent protocols for secure multiparty computation and zero knowledge non-interactive arguments of knowledge.
2018
CRYPTO
Most multi-party computation protocols allow secure computation of arithmetic circuits over a finite field, such as the integers modulo a prime. In the more natural setting of integer computations modulo $2^{k}$, which are useful for simplifying implementations and applications, no solutions with active security are known unless the majority of the participants are honest.We present a new scheme for information-theoretic MACs that are homomorphic modulo $2^k$, and are as efficient as the well-known standard solutions that are homomorphic over fields. We apply this to construct an MPC protocol for dishonest majority in the preprocessing model that has efficiency comparable to the well-known SPDZ protocol (Damgård et al., CRYPTO 2012), with operations modulo $2^k$ instead of over a field. We also construct a matching preprocessing protocol based on oblivious transfer, which is in the style of the MASCOT protocol (Keller et al., CCS 2016) and almost as efficient.
2018
CRYPTO
We present a very simple yet very powerful idea for turning any passively secure MPC protocol into an actively secure one, at the price of reducing the threshold of tolerated corruptions.Our compiler leads to a very efficient MPC protocols for the important case of secure evaluation of arithmetic circuits over arbitrary rings (e.g., the natural case of ${\mathbb {Z}}_{2^{\ell }}\!$) for a small number of parties. We show this by giving a concrete protocol in the preprocessing model for the popular setting with three parties and one corruption. This is the first protocol for secure computation over rings that achieves active security with constant overhead.
2018
PKC
We introduce a new technique that allows to give a zero-knowledge proof that a committed vector has Hamming weight bounded by a given constant. The proof has unconditional soundness and is very compact: It has size independent of the length of the committed string, and for large fields, it has size corresponding to a constant number of commitments. We show five applications of the technique that play on a common theme, namely that our proof allows us to get malicious security at small overhead compared to semi-honest security: (1) actively secure k-out-of-n OT from black-box use of 1-out-of-2 OT, (2) separable accountable ring signatures, (3) more efficient preprocessing for the TinyTable secure two-party computation protocol, (4) mixing with public verifiability, and (5) PIR with security against a malicious client.
2018
TCC
Non-Malleable Codes (NMC) were introduced by Dziembowski, Pietrzak and Wichs in ICS 2010 as a relaxation of error correcting codes and error detecting codes. Faust, Mukherjee, Nielsen, and Venturi in TCC 2014 introduced an even stronger notion of non-malleable codes called continuous non-malleable codes where security is achieved against continuous tampering of a single codeword without re-encoding.We construct information theoretically secure CNMC resilient to bit permutations and overwrites, this is the first Continuous NMC constructed outside of the split-state model.In this work we also study relations between the CNMC and parallel CCA commitments. We show that the CNMC can be used to bootstrap a Self-destruct parallel CCA bit commitment to a Self-destruct parallel CCA string commitment, where Self-destruct parallel CCA is a weak form of parallel CCA security. Then we can get rid of the Self-destruct limitation obtaining a parallel CCA commitment, requiring only one-way functions.
2017
EUROCRYPT
2017
CRYPTO
2017
CRYPTO
2017
TCC
2017
JOFC
2016
EUROCRYPT
2016
CRYPTO
2016
CRYPTO
2016
CRYPTO
2016
PKC
2016
PKC
2016
TCC
2016
TCC
2015
PKC
2015
EUROCRYPT
2014
EUROCRYPT
2014
JOFC
2014
ASIACRYPT
2013
TCC
2013
CRYPTO
2013
ASIACRYPT
2013
ASIACRYPT
2012
TCC
2012
CRYPTO
2012
PKC
2011
TCC
2011
EUROCRYPT
2011
FSE
2010
TCC
2010
TCC
2010
TCC
2010
TCC
2010
CRYPTO
2010
EUROCRYPT
2010
CHES
2009
TCC
2009
ASIACRYPT
2009
PKC
2009
PKC
2009
CRYPTO
2009
CRYPTO
2008
EUROCRYPT
2008
CRYPTO
2007
ASIACRYPT
2007
CRYPTO
2007
CRYPTO
2007
CRYPTO
2007
EUROCRYPT
2007
EUROCRYPT
2006
CRYPTO
2006
CRYPTO
2006
EUROCRYPT
2006
EUROCRYPT
2006
PKC
2006
TCC
2006
TCC
2006
JOFC
2005
CRYPTO
2005
CRYPTO
2005
PKC
2005
TCC
2004
CRYPTO
2004
EUROCRYPT
2004
TCC
2004
TCC
2004
JOFC
2004
EUROCRYPT
2003
CRYPTO
2002
ASIACRYPT
2002
CRYPTO
2002
CRYPTO
2002
EUROCRYPT
2002
PKC
2001
CRYPTO
2001
CRYPTO
2001
EUROCRYPT
2001
EUROCRYPT
2001
EUROCRYPT
2001
PKC
2000
ASIACRYPT
2000
CRYPTO
2000
EUROCRYPT
2000
EUROCRYPT
2000
PKC
2000
JOFC
1999
EUROCRYPT
1999
EUROCRYPT
1998
CRYPTO
1998
JOFC
1998
JOFC
1997
EUROCRYPT
1997
JOFC
1996
CRYPTO
1996
EUROCRYPT
1995
CRYPTO
1995
CRYPTO
1995
JOFC
1994
CRYPTO
1994
EUROCRYPT
1993
CRYPTO
1993
CRYPTO
1993
EUROCRYPT
1993
EUROCRYPT
1992
CRYPTO
1992
EUROCRYPT
1992
EUROCRYPT
1991
ASIACRYPT
1991
CRYPTO
1990
CRYPTO
1989
CRYPTO
1989
CRYPTO
1988
CRYPTO
1988
CRYPTO
1988
CRYPTO
1988
CRYPTO
1988
EUROCRYPT
1987
CRYPTO
1987
CRYPTO
1987
CRYPTO
1987
EUROCRYPT

#### Program Committees

Eurocrypt 2019
Crypto 2017
TCC 2013
Crypto 2012
Eurocrypt 2010
TCC 2009
TCC 2007
Crypto 2006
Eurocrypt 2004
Asiacrypt 2003
Eurocrypt 2002
Asiacrypt 2000
Crypto 1999
Crypto 1997
Eurocrypt 1996
Eurocrypt 1993
Crypto 1992
Eurocrypt 1990 (Program chair)
Eurocrypt 1988

#### Coauthors

Damiano Abram (1)
Mark Abspoel (3)
Divesh Aggarwal (1)
Jesús F. Almansa (1)
Benny Applebaum (1)
Thomas Attema (1)
Carsten Baum (1)
Eli Ben-Sasson (1)
Rikke Bendlin (2)
Iddo Bentov (1)
Joan Boyar (2)
Jørgen Brandt (5)
Gilles Brassard (1)
Ernest F. Brickell (1)
Jan Camenisch (1)
Ran Canetti (2)
Ignacio Cascudo (6)
David Chaum (4)
Lidong Chen (2)
Gil Cohen (1)
Ronald Cramer (24)
Claude Crépeau (1)
Morten Dahl (1)
Bernardo David (2)
Yvo Desmedt (1)
Nico Döttling (3)
Rafael Dowsley (1)
Kasper Dupont (2)
Stefan Dziembowski (3)
Daniel Escudero (6)
Oriol Farràs (1)
Sebastian Faust (3)
Nelly Fazio (1)
Serge Fehr (8)
Matthias Fitzi (2)
Gudmund Skovbjerg Frandsen (1)
Eiichiro Fujisaki (1)
Chaya Ganesh (1)
Martin Geisler (2)
Irene Giacomelli (3)
Oded Goldreich (1)
Jeroen van de Graaf (2)
Helene Haagh (2)
Robbert de Haan (1)
Carmit Hazay (1)
Martin Hirt (1)
Yuval Ishai (10)
Tomasz Kazana (1)
Marcel Keller (1)
Joe Kilian (1)
Eike Kiltz (2)
Lars R. Knudsen (2)
Jonas Kölker (1)
Maciej Koprowski (2)
Mikkel Krøigaard (2)
Mikkel Krøigaard (1)
Felipe Lacerda (1)
Peter Landrock (4)
Kasper Green Larsen (2)
Carolin Lunemann (2)
Ji Luo (1)
Philip D. MacKenzie (1)
Bernardo Magri (1)
Tal Malkin (2)
Ueli Maurer (1)
Sigurd Meldgaard (1)
Rebekah Mercer (1)
Gert Læssøe Mikkelsen (2)
Peter Bro Miltersen (1)
Kirill Morozov (1)
Pratyay Mukherjee (2)
David Naccache (1)
Antonio Nicolosi (1)
Michael Nielsen (3)
Jesper Buus Nielsen (24)
Anca Nitulescu (1)
Maciej Obremski (2)
Sabine Oechsner (1)
Tatsuaki Okamoto (1)
Claudio Orlandi (10)
Rafail Ostrovsky (1)
Valerio Pastro (1)
Thomas Brochmann Pedersen (2)
Michael Østergaard Pedersen (1)
Torben P. Pedersen (7)
René Peralta (1)
Birgit Pfitzmann (2)
Erick Purwanto (1)
Tal Rabin (1)
Varun Raj (1)
Matthieu Rambaud (1)
Samuel Ranellucci (3)
Vanishree Rao (1)
Divya Ravi (2)
Ran Raz (1)
Renato Renner (1)
João Ribeiro (1)
Noga Ron-Zewi (1)
Ron D. Rothblum (1)
Louis Salvail (9)
Alessandra Scafuro (1)
Christian Schaffner (4)
Berry Schoenmakers (1)
Peter Scholl (3)
Mark Simkin (4)
Luisa Siniscalchi (2)
Nigel P. Smart (1)
Gabriele Spini (1)
Akira Takahashi (1)
Rune Thorbek (2)
Mehdi Tibouchi (1)
Tomas Toft (1)
Roberto Trifiletti (1)
Daniele Venturi (2)
Daniel Wichs (2)
Avi Wigderson (1)
Chaoping Xing (4)
Sophia Yakoubov (2)
Chen Yuan (3)
Sarah Zakarias (4)
Lior Zichron (1)
Angela Zottarel (1)