scholarly journals On the Performance Analysis for CSIDH-Based Cryptosystems

2020 ◽  
Vol 10 (19) ◽  
pp. 6927
Author(s):  
Donghoe Heo ◽  
Suhri Kim ◽  
Young-Ho Park ◽  
Seokhie Hong
Keyword(s):  
Class Group ◽  
Security Analysis ◽  
Public Key ◽  
Security Level ◽  
Integer Vector ◽  
Ideal Class ◽  
Signature Scheme ◽  
Private Key ◽  
Fair Comparison ◽  
Exchange Algorithms

In this paper, we present the performance and security analysis for various commutative SIDH (CSIDH)-based algorithms. As CSIDH offers a smaller key size than SIDH and provides a relatively efficient signature scheme, numerous CSIDH-based key exchange algorithms have been proposed to optimize the CSIDH. In CSIDH, the private key is an ideal class in a class group, which can be represented by an integer vector. As the number of ideal classes represented by these vectors determines the security level of CSIDH, it is important to analyze whether the different vectors induce the same public key. In this regard, we generalize the existence of a collision for a base prime p≡7mod8. Based on our result, we present a new interval for the private key to have a similar security level for the various CSIDH-based algorithms for a fair comparison of the performance. Deduced from the implementation result, we conclude that for a prime p≡7mod8, CSIDH on the surface using the Montgomery curves is the most likely to be efficient. For a prime p≡3mod8, CSIDH on the floor using the hybrid method with Onuki’s collision-free method is the most likely to be efficient and secure.

Certificateless Short Signature Scheme from Bilinear Pairings

2013 ◽  
Vol 380-384 ◽  
pp. 2435-2438 ◽  
Author(s):  
Shu Rong Feng ◽  
Jiao Mo ◽  
Hua Zhang ◽  
Zheng Ping Jin
Keyword(s):  
Bilinear Pairings ◽  
Public Key ◽  
Security Level ◽  
Signature Scheme ◽  
Signature Schemes ◽  
Short Signature ◽  
Certificateless Signature ◽  
Provably Secure

Certificateless short signature schemes can not only have the advantage of certificateless signature, but also provide a short signature size in communication. However, all existing certificateless short signature schemes only proven secure against a normal adversary which can only obtain the valid signature for the original public key rather than a super adversary which can obtain the valid signature for the replaced public key. Recently, Fan et al. proposed a certificateless short signature scheme which is very efficient, but we found it is still cannot against super adversary. In this paper, we first analysis their scheme, and then present an improved scheme which can against super adversaries. Furthermore, our scheme can provide both the strongest security level and the shortest signature size compared the existed provably secure certificateless short signature scheme.

A General Threshold Signature Scheme Based on Elliptic Curve

2013 ◽  
Vol 756-759 ◽  
pp. 1339-1343
Author(s):  
Yu Lian Shang ◽  
Xiu Juan Wang ◽  
Yu Juan Li ◽  
Yu Fei Zhang
Keyword(s):  
Elliptic Curve ◽  
Communication System ◽  
Public Key ◽  
Threshold Scheme ◽  
Elliptic Curve Cryptosystem ◽  
Signature Scheme ◽  
Threshold Signature ◽  
Private Key ◽  
Generating Polynomial ◽  
Directional Transmission

Based on Elliptic Curve cryptosystem, a threshold signature scheme characterized by (k,l) joint verification for (t,n) signature is put forward. After being signed by a signer company employing (t, n) threshold signature scheme, the informationmis transmitted to a particular verifier company, and then the signature is verified through the cooperation ofkones from the verifier company withlmembers, so as to realize a directional transmission between different companies. Finally, the application examples of the company encryption communication system, the generating polynomial of company private key and public key were given. The security of this scheme is based on Shamir threshold scheme and Elliptic Curve system, and due to the advantages of Elliptic Curve, the scheme enjoys wider application in practice.

Fast Public Key Cryptosystem Based Blind Signature Scheme

2010 ◽  
Vol 20-23 ◽  
pp. 505-511
Author(s):  
Xuan Wu Zhou
Keyword(s):  
High Efficiency ◽  
Discrete Logarithm ◽  
Security Analysis ◽  
Blind Signature ◽  
Public Key ◽  
Secret Message ◽  
Polynomial Algorithms ◽  
Public Key Cryptosystem ◽  
Signature Scheme ◽  
Replay Attack

Compared with symmetric cryptosystem, asymmetric cryptosystem has much superiority in many application cases. Yet, the computation in a public key cryptosystem is much more complex than symmetric cryptosystem. In the paper, we applied HCC (Hyper-elliptic Curves Cryptosystem) as a typical fast public key cryptosystem into the designing of efficient blind signature scheme and presented an improved blind signature with fast cryptography algorithms. By utilizing probabilistic blinding algorithm, the scheme renders effective protection for the secrecy of original user, the signature generator or outer adversaries can not attack the secret message via the blinded information with effective polynomial algorithms. The scheme avoids the relevance between different signatures and interim parameters from the same original user, thus it effectively prevents signature forgery and replay attack. As security analysis for the scheme, we presented similar blind signature without relevant improving algorithms based on discrete logarithm cryptosystem. The analysis and comparison with other schemes both justify the security, reliability and high efficiency of the improved blind signature scheme regarding software and hardware application environment.

The Improved McEliece PKC and its Security Analysis

2014 ◽  
Vol 962-965 ◽  
pp. 2814-2817
Author(s):  
Si Min Liu ◽  
Jun Yao Ye
Keyword(s):  
Linear Codes ◽  
Security Analysis ◽  
Error Correcting Codes ◽  
Public Key ◽  
General Linear ◽  
Public Key Cryptosystem ◽  
Goppa Codes ◽  
Private Key ◽  
Mceliece Cryptosystem ◽  
Fast Decoding

Because the decoding problem of general linear codes is an NPC problem, at the same time Goppa codes have fast decoding algorithm, McEliece first proposed a public-key cryptosystem based on error-correcting codes. This paper constructs the largest distance codes based on metric, then improves the McEliece cryptosystem based on the largest distance codes. We've proved that the cryptosystem is able to resist the attack of getting the private key by a known public key. Finally, through the analysis of existing viable attack method, we proved the feasibility and security of the improved McEliece cryptosystem.

scholarly journals Boosted Performances of NTRUencrypt Post-Quantum Cryptosystem

2021 ◽  
Author(s):  
El Hassane Laaji ◽  
Abdelmalek Azizi
Keyword(s):  
Computational Complexity ◽  
Hash Function ◽  
Public Key ◽  
Security Level ◽  
The Public ◽  
Private Key ◽  
Multiplication Algorithm ◽  
Cipher Text ◽  
Speed Up ◽  
Quantum Cryptosystem

The bottleneck of all cryptosystems is the difficulty of the computational complexity of the polynomials multiplication, vectors multiplication, etc. Thus most of them use some algorithms to reduce the complexity of the multiplication like NTT, Montgomery, CRT, and Karatsuba algorithms, etc. We contribute by creating a new release of NTRUencrypt1024 with great improvement, by using our own polynomials multiplication algorithm operate in the ring of the form Rq=Zq[X]/(XN+1), combined to Montgomery algorithm rather than using the NTT algorithm as used by the original version. We obtained a good result, our implementation outperforms the original one by speed-up of a factor up to (X10) for encryption and a factor up to (X11) for decryption functions. We note that our improved implementation used the latest hash function standard SHA-3, and reduce the size of the public key, private key, and cipher-text from 4097 bytes to 2049 bytes with the same security level.

scholarly journals HORSIC+: An Efficient Post-Quantum Few-Time Signature Scheme

2021 ◽  
Vol 11 (16) ◽  
pp. 7350
Author(s):  
Jaeheung Lee ◽  
Yongsu Park
Keyword(s):  
Security Analysis ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Security Level ◽  
Signature Scheme ◽  
Signature Schemes ◽  
Security Proof ◽  
Time Signature ◽  
Resistant Family ◽  
Cryptographic Hash Functions

It is well known that conventional digital signature algorithms such as RSA and ECDSA are vulnerable to quantum computing attacks. Hash-based signature schemes are attractive as post-quantum signature schemes in that it is possible to calculate the quantitative security level and the security is proven. SPHINCS is a stateless hash-based signature scheme and introduces HORST few-time signature scheme which is an improvement of HORS. However, HORST as well as HORS suffers from pretty large signature sizes. HORSIC is proposed to reduce the signature size, yet does not provide in-depth security analysis. In this paper, we propose HORSIC+, which is an improvement of HORSIC. HORSIC+ differs from HORSIC in that HORSIC+ does not apply f as a plain function to the signature key, but uses a member of a function family. In addition, HORSIC+ uses the chaining function similar to W-OTS+. These enable the strict security proof without the need for the used function family to be a permutation or collision resistant. HORSIC+ is existentially unforgeable under chosen message attacks, assuming a second-preimage resistant family of undetectable one-way functions and cryptographic hash functions in the random oracle model. HORSIC+ reduces the signature size by as much as 37.5% or 18.75% compared to HORS and by as much as 61.5% or 45.8% compared to HORST for the same security level.

Security Analysis and the Improvement of Multi-Proxy Multi-Signature Scheme

2014 ◽  
Vol 513-517 ◽  
pp. 1680-1683
Author(s):  
Xing Hua Zhang
Keyword(s):  
Security Analysis ◽  
Public Key ◽  
Signature Scheme ◽  
Signature Schemes ◽  
The Public ◽  
Efficient Scheme ◽  
Delegation Of Powers

Many original signers can put a delegation of powers to many proxy signers, it is a representation of all the original signers to generate a plurality of proxy signers in the multi-proxy multi-signature scheme. It is analyzed to the existing multi-proxy multi-signature schemes in this paper , the verification equation is improved. A new secure and efficient scheme is proposed. The security analysis shows that the verification equations of the new scheme is more safe. The new scheme can resist the public-key substitution attack, can resist the coalition attack.

Public Key Cryptosystem and Signature Scheme over the Ring Z[3√2]

2014 ◽  
Vol 513-517 ◽  
pp. 4509-4512
Author(s):  
Xue Dong Dong ◽  
Xin Peng Jing
Keyword(s):  
Digital Signature ◽  
Public Key ◽  
Periodic Change ◽  
Security Level ◽  
Public Key Cryptosystem ◽  
Signature Scheme ◽  
Group Of Units ◽  
Original Scheme ◽  
Primitive Roots ◽  
Digital Signature Scheme

In this paper, the extended ElGamal public key cryptosystem and digital signature scheme with appendix are described in the setting of the group of units of the ring.Elements of the group of units with the larger order are used as the base elements in the proposed extension instead of primitive roots used in the original scheme. Proposed schemes make periodic change of the group and base elements to provide necessary security level.

scholarly journals Defeating MITM Attacks on Cryptocurrency Exchange Accounts with Individual User Keys

2021 ◽  
Vol 13 (1) ◽  
pp. 51-64
Author(s):  
Cheman Shaik
Keyword(s):  
Elliptic Curve ◽  
Elliptic Curve Cryptography ◽  
Security Analysis ◽  
Public Key ◽  
Public And Private ◽  
The Public ◽  
Individual User ◽  
Private Key ◽  
Authentication Schemes

Presented herein is a User-SpecificKey Scheme based on Elliptic Curve Cryptography that defeats man-inthe-middle attacks on cryptocurrency exchange accounts. In this scheme, a separate public and private key pair is assigned to every account and the public key is shifted either forward or backward on the elliptic curve by a difference of the account user’s password. When a user logs into his account, the server sends the shifted public key of his account. The user computes the actual public key of his account by reverse shifting the shifted public key exactly by a difference of his password. Alternatively, shifting can be applied to the user’s generator instead of the public key. Described in detail is as to how aman-in-the-middle attack takes place and how the proposed scheme defeats the attack. Provided detailed security analysis in both the cases of publickey shifting and generator shifting. Further, compared the effectiveness of another three authentication schemes in defending passwords against MITM attacks.

scholarly journals Analysis of theoretical security level of PDF Encryption mechanism based on X.509 certificates

2017 ◽  
Vol 66 (4) ◽  
pp. 95-110
Author(s):  
Joanna Dmitruk ◽  
Michał Glet
Keyword(s):  
Security Analysis ◽  
Public Key Infrastructure ◽  
Public Key ◽  
Security Level ◽  
Security Mechanism ◽  
Content Security

PDF Encryption is a content security mechanism developed and used by Adobe in their products. In this paper, we have checked a theoretical security level of a variant that uses public key infrastructure and X.509 certificates. We have described a basis of this mechanism and we have performed a simple security analysis. Then, we have showed possible tweaks and security improvements. At the end, we have given some recommendations that can improve security of a content secured with PDF Encryption based on X.509 certificates. Keywords: DRM, cryptography, security level, PDF Encryption, Adobe, X.509

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