О повышении безопасности схем подписи Эль-Гамаля

2021 ◽  
Vol 12 (3) ◽  
pp. 5-30
Author(s):  
Евгений Константинович Алексеев ◽  
Evgeny Konstantinovich Alekseev ◽  
Л Р Ахметзянова ◽  
L R Akhmetzyanova ◽  
Александра Алексеевна Бабуева ◽  
...  
Keyword(s):  
Strong Unforgeability

Предлагается способ модификации схем подписи Эль-Гамаля (в частности, ГОСТ Р 34.10-2012), повышающий безопасность в сценариях использования в слабодоверенном окружении (при отсутствии надежных датчиков случайных чисел). Для анализа стойкости модифицированной схемы подписи предложена модель противника SUF-CMRA (Strong Unforgeability under Chosen Message and Randomness Attack). В этой модели получена оценка стойкости модифицированной схемы (в модели со случайным оракулом) в виде функции от стойкости базовой схемы подписи в модели SUF-CMA и стойкости функции HMAC в модели PRF.

scholarly journals A Strongly Unforgeable Certificateless Signature Scheme and Its Application in IoT Environments

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2692 ◽  
Author(s):  
Xiaodong Yang ◽  
Xizhen Pei ◽  
Guilan Chen ◽  
Ting Li ◽  
Meiding Wang ◽  
...  
Keyword(s):  
Security Requirements ◽  
Widespread Application ◽  
Random Oracles ◽  
Replay Attacks ◽  
Security Research ◽  
Viable Solution ◽  
Iot Devices ◽  
Certificateless Signature ◽  
The Internet Of Things ◽  
Strong Unforgeability

With the widespread application of the Internet of Things (IoT), ensuring communication security for IoT devices is of considerable importance. Since IoT data are vulnerable to eavesdropping, tampering, forgery, and other attacks during an open network transmission, the integrity and authenticity of data are fundamental security requirements in the IoT. A certificateless signature (CLS) is a viable solution for providing data integrity, data authenticity, and identity identification in resource-constrained IoT devices. Therefore, designing a secure and efficient CLS scheme for IoT environments has become one of the main objectives of IoT security research. However, the existing CLS schemes rarely focus on strong unforgeability and replay attacks. Herein, we design a novel CLS scheme to protect the integrity and authenticity of IoT data. In addition to satisfying the strong unforgeability requirement, the proposed scheme also resists public key replacement attacks, malicious-but-passive key-generation-centre attacks, and replay attacks. Compared with other related CLS schemes without random oracles, our CLS scheme has a shorter private key, stronger security, and lower communication and computational costs.

scholarly journals Strongly Unforgeable Ring Signature Scheme from Lattices in the Standard Model

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Geontae Noh ◽  
Ji Young Chun ◽  
Ik Rae Jeong
Keyword(s):  
Standard Model ◽  
Signature Scheme ◽  
Signature Schemes ◽  
Ring Signature ◽  
Arbitrary Ring ◽  
Computational Overhead ◽  
The Standard Model ◽  
First Time ◽  
Strong Unforgeability

In a ring signature scheme, a user selects an arbitrary ring to be able to sign a message on behalf of the ring without revealing the signer’s identity. Whistle-blowers especially find this useful. To date, various ring signature schemes have been proposed, all considered to be secure as existentially unforgeable with respect to insider corruption; that is, an adversary who chooses ring-message pairs for which he requests signatures, corrupts honest users, and obtains their signing keys can not produce forgeries for new ring-message pairs. Lattice-based ring signature schemes offer lower computational overhead and security from quantum attacks. In this paper, we offer a lattice-based scheme. We begin by showing that the existing ring signature schemes are not sufficiently secure, because existential unforgeability still permits a signer to potentially produce a new signature on previously signed messages. Furthermore, we show that existing ring signature schemes from lattices are not even existentially unforgeable with respect to insider corruption. We then improve previous schemes by applying, for the first time, the concept of strong unforgeability with respect to insider corruption to a ring signature scheme in lattices. This offers more security than any previous ring signature scheme: adversaries cannot produce new signatures for any ring-message pair, including previously signed ring-message pairs.

Some Thoughts on Strong Unforgeability in Ring Signature Schemes

2012 ◽  
Vol 457-458 ◽  
pp. 773-779
Author(s):  
Chen Wang
Keyword(s):  
Standard Model ◽  
Signature Scheme ◽  
Signature Schemes ◽  
Ring Signature ◽  
Modified Method ◽  
Ring Signatures ◽  
The Standard Model ◽  
Strong Unforgeability

A signature scheme is strongly unforgeable if the adversary cannot produce a new signature even on a queried message. Some methods have been proposed to enhance some regular signatures. However, if applied to ring signatures, such methods will break the anonymity, which is the soul of ring signatures. We introduce a modified method which can achieve both strong unforgeability and anonymity in the standard model. Applying this method to Shacham-Waters scheme, we get the first ring signature with strong unforgeability in the stand model.

scholarly journals A Fuzzy Identity-Based Signature Scheme from Lattices in the Standard Model

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Chunli Yang ◽  
Shihui Zheng ◽  
Licheng Wang ◽  
Miaomiao Tian ◽  
Lize Gu ◽  
...  
Keyword(s):  
Standard Model ◽  
Secret Key ◽  
Random Oracles ◽  
Sharing Scheme ◽  
The Standard Model ◽  
Identity Based ◽  
Shamir Secret Sharing Scheme ◽  
Fuzzy Identity ◽  
Shamir Secret Sharing ◽  
Strong Unforgeability

A fuzzy identity-based signature (FIBS) scheme allows a user with identityIDto issue a signature that could be verified with identityID'if and only ifIDandID'lie within a certain distance. To obtain an FIBS scheme that can resist known quantum attacks, we use the double-trapdoor technique from ABB10a for secret key extracting and the vanishing trapdoor technique from Boyen10 for message signing. In addition, in order to reflect the functionality of fuzziness, Shamir secret sharing scheme is also used in our construction. In this paper, we propose an FIBS scheme from lattices and prove that this new scheme achieves strong unforgeability under selective chosen-identity and adaptive chosen-message attacks (SU-sID-CMA) in the standard model. To the best of our knowledge, our scheme is not only the first FIBS scheme from lattices without random oracles but also the first FIBS scheme that achieves strong unforgeability.

Certificateless Signature with Strong Unforgeability in the Standard Model

Informatica ◽  
2015 ◽  
Vol 26 (4) ◽  
pp. 663-684 ◽  
Author(s):  
Ying-Hao Hung ◽  
Sen-Shan Huang ◽  
Yuh-Min Tseng ◽  
Tung-Tso Tsai
Keyword(s):  
Standard Model ◽  
The Standard Model ◽  
Certificateless Signature ◽  
Strong Unforgeability

Strong unforgeability in group signature schemes

2009 ◽  
Vol 31 (4) ◽  
pp. 856-862 ◽  
Author(s):  
Haeryong Park ◽  
Seongan Lim ◽  
Ikkwon Yie ◽  
Kitae Kim ◽  
Junghwan Song
Keyword(s):  
Group Signature ◽  
Signature Schemes ◽  
Strong Unforgeability

scholarly journals Strongly Unforgeable Certificateless Signature Resisting Attacks from Malicious-But-Passive KGC

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Wenjie Yang ◽  
Jian Weng ◽  
Weiqi Luo ◽  
Anjia Yang
Keyword(s):  
Standard Model ◽  
Digital Signature ◽  
Theory And Practice ◽  
Key Generation ◽  
Random Oracles ◽  
The Standard Model ◽  
Certificateless Signature ◽  
Adversarial Model ◽  
Strong Unforgeability

In digital signature, strong unforgeability requires that an attacker cannot forge a new signature on any previously signed/new messages, which is attractive in both theory and practice. Recently, a strongly unforgeable certificateless signature (CLS) scheme without random oracles was presented. In this paper, we firstly show that the scheme fails to achieve strong unforgeability by forging a new signature on a previously signed message under its adversarial model. Then, we point out that the scheme is also vulnerable to the malicious-but-passive key generation center (MKGC) attacks. Finally, we propose an improved strongly unforgeable CLS scheme in the standard model. The improved scheme not only meets the requirement of strong unforgeability but also withstands the MKGC attacks. To the best of our knowledge, we are the first to prove a CLS scheme to be strongly unforgeable against the MKGC attacks without using random oracles.

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