Abstract In the case of standard LWE samples
(A,b = sA + e) ( A , b = sA + e ) ,
A A is typically uniformly over
Zqn×m Z q n × m . Under the
DLWE DLWE assumption, the conditional distribution of
s∣(A,b) s | ( A , b ) and
s s is expected to be consistent. However, in the case where an adversary chooses
A A adaptively, the disparity between the two entities may be larger. In this work, our primary focus is on the quantification of the Average Conditional Min-Entropy
H~∞(s∣sA + e) H ~ ∞ ( s | sA + e ) of
s s , where
A A is chosen by the adversary. Brakerski and Döttling answered the question in one case: they proved that when
s s is uniformly chosen from
Zqn Z q n , it holds that
H~∞(s∣sA + e)∝ρσ(Λq(A)) H ~ ∞ ( s | sA + e ) ∝ ρ σ ( Λ q ( A
Blockchain technology has become a research hotspot in recent years with the prominent characteristics as public, distributed and decentration. And blockchain-enabled internet of things (BIoT) has a tendency to make a revolutionary change for the internet of things (IoT) which requires distributed trustless consensus. However, the scalability and security issues become particularly important with the dramatically increasing number of IoT devices. Especially, with the development of quantum computing, many extant cryptographic algorithms applied in blockchain or BIoT systems are vulnerable to the quantum attacks. In this paper, an anti-quantum proxy blind signature scheme based on the lattice cryptography has been proposed, which can provide user anonymity and untraceability in the distributed applications of BIoT. Then, the security proof of the proposed scheme can derive that it is secure in random oracle model, and the efficiency analysis can indicate it is efficient than other similar literatures.
Electronic cash (e-cash) has become major payment way in the era of internet of things. However, the leakage of user privacy and transaction data is becoming more and more serious in e-cash system. To solve these problems, we construct a new certificateless blind signcryption from NTRU lattice (NTRUL-CLBSC) suitable for e-cash. NTRUL-CLBSC has low communication overhead and high calculation efficiency because of small storage space and short key size in number theory research unit (NTRU) lattice. Based on RSIS and DNCC problems in NTRU lattice, NTRUL-CLBSC can guarantee the anti-quantum, anti-forgery, confidentiality and blindness, and there is no key escrow and certificate management in e-cash application.