Group-oriented (t, n) threshold digital signature scheme and digital multisignature

Harn, Lein

doi:10.1049/ip-cdt:19941293

Cited by 239 publications

(120 citation statements)

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“…In a threshold signature scheme [19], when there are t or more than t group members, a group signature can be generated successfully. The group signature can be verified by any verifier using the group public key.…”

Section: Gf Pmentioning

confidence: 99%

“…When there are t or more than t group members, the group cipher-text can be decrypted successfully. All existing threshold cryptographic algorithms [19][20][21][22][23][24][25][26] only consider the situation when all participating users are legitimate group members. In this paper, we point out that when there are more than t participating users and computed valued are released asynchronously in a threshold application, an attacker can obtain the valid output of the application and therefore, can impersonate to be a legitimate group member without being detected.…”

Section: Gf Pmentioning

confidence: 99%

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Asynchronous Secret Reconstruction and Its Application to the Threshold Cryptography

Harn¹,

Lin²

2014

IJCNS

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In Shamir's ( ) t n , threshold of the secret sharing scheme, a secret s is divided into n shares by a dealer and is shared among n shareholders in such a way that (a) the secret can be reconstructed when there are t or more than t shares; and (b) the secret cannot be obtained when there are fewer than t shares. In the secret reconstruction, participating users can be either legitimate shareholders or attackers. Shamir's scheme only considers the situation when all participating users are legitimate shareholders. In this paper, we show that when there are more than t users participating and shares are released asynchronously in the secret reconstruction, an attacker can always release his share last. In such a way, after knowing t valid shares of legitimate shareholders, the attacker can obtain the secret and therefore, can successfully impersonate to be a legitimate shareholder without being detected. We propose a simple modification of Shamir's scheme to fix this security problem. Threshold cryptography is a research of group-oriented applications based on the secret sharing scheme. We show that a similar security problem also exists in threshold cryptographic applications. We propose a modified scheme to fix this security problem as well.

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Section: Gf Pmentioning

confidence: 99%

Section: Gf Pmentioning

confidence: 99%

Asynchronous Secret Reconstruction and Its Application to the Threshold Cryptography

Harn¹,

Lin²

2014

IJCNS

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“…For example, threshold cryptography, first introduced by Desmedt [5], is the application of secret-sharing with public-key algorithms. Among various threshold cryptosystems, some are based on ElGamal [6,7], some are based on RSA [8][9][10][11], some are based on Elliptic Curves [12,13], and some are based on Pairing [14]. In these protocols, shares are either used to generate a digital signature or used to decrypt a ciphertext.…”

Section: Security and Communication Networkmentioning

confidence: 99%

How to Share Secret Efficiently over Networks

Harn

Hsu

Xia

et al. 2017

Security and Communication Networks

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In a secret-sharing scheme, the secret is shared among a set of shareholders, and it can be reconstructed if a quorum of these shareholders work together by releasing their secret shares. However, in many applications, it is undesirable for nonshareholders to learn the secret. In these cases, pairwise secure channels are needed among shareholders to exchange the shares. In other words, a shared key needs to be established between every pair of shareholders. But employing an additional key establishment protocol may make the secret-sharing schemes significantly more complicated. To solve this problem, we introduce a new type of secret-sharing, called protected secret-sharing (PSS), in which the shares possessed by shareholders not only can be used to reconstruct the original secret but also can be used to establish the shared keys between every pair of shareholders. Therefore, in the secret reconstruction phase, the recovered secret is only available to shareholders but not to nonshareholders. In this paper, an information theoretically secure PSS scheme is proposed, its security properties are analyzed, and its computational complexity is evaluated. Moreover, our proposed PSS scheme also can be applied to threshold cryptosystems to prevent nonshareholders from learning the output of the protocols.

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“…Early work in the field is due to Boyd [7], Desmedt [19], Croft and Harris [17], Frankel [24], and Desmedt and Frankel [20]. Work in threshold cryptography for discrete-log based cryptosystems includes, for example, Desmedt and Frankel [20], Hwang [32], Pedersen [40], Cerecedo et al [12], Harn [30], Langford [34], Gennaro et al [29], Park and Kurosawa [39], Herzberg et al [31], and Frankel et al [26].…”

Section: Related Workmentioning

confidence: 99%

An Efficient Two-Party Public Key Cryptosystem Secure against Adaptive Chosen Ciphertext Attack

MacKenzie

2002

Public Key Cryptography — PKC 2003

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Abstract.We propose an efficient two-party public key cryptosystem that is secure against adaptive chosen ciphertext attack, based on the hardness of Decision Diffie-Hellman (DDH). Specifically, we show that the two parties together can decrypt ciphertexts, but neither can alone. Our system is based on the Cramer-Shoup cryptosystem. Previous results on efficient threshold cryptosystems secure against adaptive chosen ciphertext attack required either (1) a strict majority of uncorrupted decryption servers, and thus do not apply to the two-party scenario, or (2) the random oracle assumption, and thus were not proven secure in the "standard" model.

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Group-oriented (t, n) threshold digital signature scheme and digital multisignature

Cited by 239 publications

References 0 publications

Asynchronous Secret Reconstruction and Its Application to the Threshold Cryptography

Asynchronous Secret Reconstruction and Its Application to the Threshold Cryptography

How to Share Secret Efficiently over Networks

An Efficient Two-Party Public Key Cryptosystem Secure against Adaptive Chosen Ciphertext Attack

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