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59
A Secure and Optimally Efficient MultiAuthority Election Scheme
, 1997
"... Abstract. In this paper we present a new multiauthority secretballot election scheme that guarantees privacy, universal verifiability, and robustness. It is the first scheme for which the performance is optimal in the sense that time and communication complexity is minimal both for the individual ..."
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Cited by 245 (6 self)
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Abstract. In this paper we present a new multiauthority secretballot election scheme that guarantees privacy, universal verifiability, and robustness. It is the first scheme for which the performance is optimal in the sense that time and communication complexity is minimal both for the individual voters and the authorities. An interesting property of the scheme is that the time and communication complexity for the voter is independent of the number of authorities. A voter simply posts a single encrypted message accompanied by a compact proof that it contains a valid vote. Our result is complementary to the result by Cramer, Franklin, Schoenmakers, and Yung in the sense that in their scheme the work for voters is linear in the number of authorities but can be instantiated to yield informationtheoretic privacy, while in our scheme the voter’s effort is independent of the number of authorities but always provides computational privacyprotection. We will also point out that the majority of proposed voting schemes provide computational privacy only (often without even considering the lack of informationtheoretic privacy), and that our new scheme is by far superior to those schemes. 1
Signature schemes and anonymous credentials from bilinear maps
, 2004
"... We propose a new and efficient signature scheme that is provably secure in the plain model. The security of our scheme is based on a discretelogarithmbased assumption put forth by Lysyanskaya, Rivest, Sahai, and Wolf (LRSW) who also showed that it holds for generic groups and is independent of th ..."
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Cited by 198 (25 self)
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We propose a new and efficient signature scheme that is provably secure in the plain model. The security of our scheme is based on a discretelogarithmbased assumption put forth by Lysyanskaya, Rivest, Sahai, and Wolf (LRSW) who also showed that it holds for generic groups and is independent of the decisional DiffieHellman assumption. We prove security of our scheme under the LRSW assumption for groups with bilinear maps. We then show how our scheme can be used to construct efficient anonymous credential systems as well as group signature and identity escrow schemes. To this end, we provide efficient protocols that allow one to prove in zeroknowledge the knowledge of a signature on a committed (or encrypted) message and to obtain a signature on a committed message.
Direct Anonymous Attestation
, 2004
"... This paper describes the direct anonymous attestation scheme (DAA). This scheme was adopted by the Trusted Computing Group as the method for remote authentication of a hardware module, called trusted platform module (TPM), while preserving the privacy of the user of the platform that contains the ..."
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Cited by 159 (18 self)
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This paper describes the direct anonymous attestation scheme (DAA). This scheme was adopted by the Trusted Computing Group as the method for remote authentication of a hardware module, called trusted platform module (TPM), while preserving the privacy of the user of the platform that contains the module. Direct anonymous attestation can be seen as a group signature without the feature that a signature can be opened, i.e., the anonymity is not revocable. Moreover, DAA allows for pseudonyms, i.e., for each signature a user (in agreement with the recipient of the signature) can decide whether or not the signature should be linkable to another signature. DAA furthermore allows for detection of "known" keys: if the DAA secret keys are extracted from a TPM and published, a verifier can detect that a signature was produced using these secret keys. The scheme is provably secure in the random oracle model under the strong RSA and the decisional Di#eHellman assumption.
Fast batch verification for modular exponentiation and digital signatures
, 1998
"... Abstract Many tasks in cryptography (e.g., digital signature verification) call for verification of a basicoperation like modular exponentiation in some group: given ( g, x, y) check that gx = y. Thisis typically done by recomputing gx and checking we get y. We would like to do it differently,and f ..."
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Cited by 140 (2 self)
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Abstract Many tasks in cryptography (e.g., digital signature verification) call for verification of a basicoperation like modular exponentiation in some group: given ( g, x, y) check that gx = y. Thisis typically done by recomputing gx and checking we get y. We would like to do it differently,and faster. The approach we use is batching. Focusing first on the basic modular exponentiation operation, we provide some probabilistic batch verifiers, or tests, that verify a sequence of modular exponentiations significantly faster than the naive recomputation method. This yields speedupsfor several verification tasks that involve modular exponentiations.
Proving in ZeroKnowledge that a Number is the Product of Two Safe Primes
, 1998
"... This paper presents the first efficient statistical zeroknowledge protocols to prove statements such as: A committed number is a pseudoprime. ..."
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Cited by 131 (13 self)
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This paper presents the first efficient statistical zeroknowledge protocols to prove statements such as: A committed number is a pseudoprime.
The Elliptic Curve Digital Signature Algorithm (ECDSA)
, 1999
"... The Elliptic Curve Digital Signature Algorithm (ECDSA) is the elliptic curve analogue of the Digital Signature Algorithm (DSA). It was accepted in 1999 as an ANSI standard, and was accepted in 2000 as IEEE and NIST standards. It was also accepted in 1998 as an ISO standard, and is under consideratio ..."
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Cited by 119 (5 self)
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The Elliptic Curve Digital Signature Algorithm (ECDSA) is the elliptic curve analogue of the Digital Signature Algorithm (DSA). It was accepted in 1999 as an ANSI standard, and was accepted in 2000 as IEEE and NIST standards. It was also accepted in 1998 as an ISO standard, and is under consideration for inclusion in some other ISO standards. Unlike the ordinary discrete logarithm problem and the integer factorization problem, no subexponentialtime algorithm is known for the elliptic curve discrete logarithm problem. For this reason, the strengthperkeybit is substantially greater in an algorithm that uses elliptic curves. This paper describes the ANSI X9.62 ECDSA, and discusses related security, implementation, and interoperability issues. Keywords: Signature schemes, elliptic curve cryptography, DSA, ECDSA.
Robust and Efficient Sharing of RSA Functions
, 1996
"... We present two efficient protocols which implement robust threshold RSA signature schemes, where the power to sign is shared by N players such that any subset of more then T signers can collaborate to produce a valid RSA signature on any given message, but no subset of fewer than T corrupted players ..."
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Cited by 83 (11 self)
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We present two efficient protocols which implement robust threshold RSA signature schemes, where the power to sign is shared by N players such that any subset of more then T signers can collaborate to produce a valid RSA signature on any given message, but no subset of fewer than T corrupted players can forge a signature. Our protocols are robust in the sense that the correct signature is computed even if up to T players behave in arbitrarily malicious way during the signature protocol. This in particular includes the cases of players that refuse to participate or that generate incorrect partial signatures. Our protocols achieve fault tolerance T of N=2, which is optimal. Our protocols are also very efficient, as the computation performed by each player is comparable to the computation cost of a single RSA signature. Robust threshold signature schemes have very important applications, since they provide increased security and availability for a signing server (e.g. a certification auth...
Separability and Efficiency for Generic Group Signature Schemes (Extended Abstract)
, 1999
"... A cryptographic protocol possesses separability if the participants can choose their keys independently of each other. This is advantageous from a keymanagement as well as from a security point of view. This paper focuses on separability in group signature schemes. Such schemes allow a group member ..."
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Cited by 77 (13 self)
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A cryptographic protocol possesses separability if the participants can choose their keys independently of each other. This is advantageous from a keymanagement as well as from a security point of view. This paper focuses on separability in group signature schemes. Such schemes allow a group member to sign messages anonymously on the group's behalf. However, in case of this anonymity's misuse, a trustee can reveal the originator of a signature. We provide a generic fully separable group signature scheme and present an ecient instantiation thereof. The scheme is suited for large groups; the size of the group's public key and the length of signatures do not depe...
RSABased Undeniable Signatures
"... We present the first undeniable signatures scheme based on RSA. Since their introduction in 1989 a significant amount of work has been devoted to the investigation of undeniable signatures. So far, this work has been based on discrete log systems. In contrast, our scheme uses regular RSA signature ..."
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Cited by 76 (5 self)
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We present the first undeniable signatures scheme based on RSA. Since their introduction in 1989 a significant amount of work has been devoted to the investigation of undeniable signatures. So far, this work has been based on discrete log systems. In contrast, our scheme uses regular RSA signatures to generate undeniable signatures. In this new setting, both the signature and verification exponents of RSA are kept secret by the signer, while the public key consists of a composite modulus and a sample RSA signature on a single public message. Our scheme possesses several attractive properties. First of all, provable security, as forging the undeniable signatures is as hard as forging regular RSA signatures. Second, both the confirmation and denial protocols are zeroknowledge. In addition, these protocols are efficient (particularly, the confirmation protocol involves only two rounds of communication and a small number of exponentiations). Furthermore the RSAbased structure of our scheme provides with simple and elegant solutions to add several of the more advanced properties of undeniable signatures found in the literature, including convertibility of the undeniable signatures (into publicly verifiable ones), the possibility to delegate the ability to confirm and deny signatures to a third party without giving up the power to sign, and the existence of distributed (threshold) versions of the signing and confirmation operations. Due to the above properties and the fact that our undeniable signatures are identical in form to standard RSA signatures, the scheme we present becomes a very attractive candidate for practical implementations.
An efficient threshold public key cryptosystem secure against adaptive chosen ciphertext attack
, 1999
"... Abstract. This paper proposes a simple threshold PublicKey Cryptosystem (PKC) which is secure against adaptive chosen ciphertext attack, under the Decisional DiffieHellman (DDH) intractability assumption. Previously, it was shown how to design noninteractive threshold PKC secure under chosen ciph ..."
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Cited by 66 (0 self)
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Abstract. This paper proposes a simple threshold PublicKey Cryptosystem (PKC) which is secure against adaptive chosen ciphertext attack, under the Decisional DiffieHellman (DDH) intractability assumption. Previously, it was shown how to design noninteractive threshold PKC secure under chosen ciphertext attack, in the randomoracle model and under the DDH intractability assumption [25]. The randomoracle was used both in the proof of security and to eliminate interaction. General completeness results for multiparty computations [6,13] enable in principle converting any single server PKC secure against CCA (e.g., [19,17]) into a threshold one, but the conversions are inefficient and require much interaction among the servers for each ciphertext decrypted. The recent work by Cramer and Shoup [17] on single server PKC secure against adaptive CCA is the starting point for the new proposal. 1