A CUBIC EL-GAMAL ENCRYPTION SCHEME BASED ON LUCAS SEQUENCE AND ELLIPTIC CURVE

2021 ◽  
Vol 10 (11) ◽  
pp. 3439-3447
Author(s):  
T. J. Wong ◽  
L. F. Koo ◽  
F. H. Naning ◽  
A. F. N. Rasedee ◽  
M. M. Magiman ◽  
...  

The public key cryptosystem is fundamental in safeguard communication in cyberspace. This paper described a new cryptosystem analogous to El-Gamal encryption scheme, which utilizing the Lucas sequence and Elliptic Curve. Similar to Elliptic Curve Cryptography (ECC) and Rivest-Shamir-Adleman (RSA), the proposed cryptosystem requires a precise hard mathematical problem as the essential part of security strength. The chosen plaintext attack (CPA) was employed to investigate the security of this cryptosystem. The result shows that the system is vulnerable against the CPA when the sender decrypts a plaintext with modified public key, where the cryptanalyst able to break the security of the proposed cryptosystem by recovering the plaintext even without knowing the secret key from either the sender or receiver.

2021 ◽  
Vol 10 (11) ◽  
pp. 3439-3447
Author(s):  
T. J. Wong ◽  
L. F. Koo ◽  
F. H. Naning ◽  
A. F. N. Rasedee ◽  
M. M. Magiman ◽  
...  

The public key cryptosystem is fundamental in safeguard communication in cyberspace. This paper described a new cryptosystem analogous to El-Gamal encryption scheme, which utilizing the Lucas sequence and Elliptic Curve. Similar to Elliptic Curve Cryptography (ECC) and Rivest-Shamir-Adleman (RSA), the proposed cryptosystem requires a precise hard mathematical problem as the essential part of security strength. The chosen plaintext attack (CPA) was employed to investigate the security of this cryptosystem. The result shows that the system is vulnerable against the CPA when the sender decrypts a plaintext with modified public key, where the cryptanalyst able to break the security of the proposed cryptosystem by recovering the plaintext even without knowing the secret key from either the sender or receiver.


2021 ◽  
Vol 13 (1) ◽  
pp. 51-64
Author(s):  
Cheman Shaik

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.


Cryptography ◽  
2020 ◽  
pp. 306-315
Author(s):  
Daya Sagar Gupta ◽  
G. P. Biswas

This paper presents a new homomorphic public-key encryption scheme based on the elliptic curve cryptography (HPKE-ECC). This HPKE-ECC scheme allows public computation on encrypted data stored on a cloud in such a manner that the output of this computation gives a valid encryption of some operations (addition/multiplication) on original data. The cloud system (server) has only access to the encrypted files of an authenticated end-user stored in it and can only do computation on these stored files according to the request of an end-user (client). The implementation of proposed HPKE-ECC protocol uses the properties of elliptic curve operations as well as bilinear pairing property on groups and the implementation is done by Weil and Tate pairing. The security of proposed encryption technique depends on the hardness of ECDLP and BDHP.


2003 ◽  
Vol 10 (16) ◽  
Author(s):  
Ivan B. Damgård ◽  
Mads J. Jurik

We propose a public-key cryptosystem which is derived from the Paillier cryptosystem. The scheme inherits the attractive homomorphic properties of Paillier encryption. In addition, we achieve two new properties: First, all users can use the same modulus when generating key pairs, this allows more efficient proofs of relations between different encryptions. Second, we can construct a threshold decryption protocol for our scheme that is length flexible, i.e., it can handle efficiently messages of arbitrary length, even though the public key and the secret key shares held by decryption servers are of fixed size. We show how to apply this cryptosystem to build:<br /> <br />1) a self-tallying election scheme with perfect ballot secrecy. This is a small voting system where the result can be computed from the submitted votes without the need for decryption servers. The votes are kept secret unless the cryptosystem can be broken, regardless of the number of cheating parties. This is in contrast to other known schemes that usually require a number of decryption servers, the majority of which must be honest.<br /> <br />2) a length-flexible mix-net which is universally verifiable, where the size of keys and ciphertexts do not depend on the number of mix servers, and is robust against a corrupt minority. Mix-nets can provide anonymity by shuffling messages to provide a random permutation of input ciphertexts to the output plaintexts such that no one knows which plaintexts relate to which ciphertexts. The mix-net inherits several nice properties from the underlying cryptosystem, thus making it useful for a setting with small messages or high computational power, low-band width and that anyone can verify that the mix have been done correctly.


2012 ◽  
Vol 12 (1) ◽  
pp. 65
Author(s):  
Winsy Weku

MODEL PROYEKSI (X/Z2, Y/Z2) PADA KURVA HESIAN SECARA PARALEL MENGGUNAKAN MEKANISME KRIPTOGRAFI KURVA ELIPTIKABSTRAK Suatu kunci publik, Elliptic Curve Cryptography (ECC) dikenal sebagai algoritma yang paling aman yang digunakan untuk memproteksi informasi sepanjang melakukan transmisi.  ECC dalam komputasi aritemetika didapatkan berdasarkan operasi inversi modular. Inversi modular adalah operasi aritmetika dan operasi yang sangat panjang yang didapatkan berdasar ECC crypto-processor. Penggunaan koordinat proyeksi untuk menentukan Kurva Eliptik/ Elliptic Curves pada kenyataannya untuk memastikan koordinat proyeksi yang sebelumnya telah ditentukan oleh kurva eliptik E: y2 = x3 + ax + b yang didefinisikan melalui Galois field GF(p)untuk melakukan operasi aritemtika dimana dapat diketemukan bahwa terdapat beberapa multiplikasi yang dapat diimplementasikan secara paralel untuk mendapatkan performa yang tinggi. Pada penelitian ini, akan dibahas tentang sistem koordinat proyeksi Hessian (X/Z2, Y,Z2) untuk meningkatkan operasi penggandaan ECC dengan menggunakan pengali paralel untuk mendapatkan paralel yang maksimum untuk mendapatkan hasil maksimal. Kata kunci: Elliptic Curve Cryptography, Public-Key Cryptosystem, Galois Fields of Primes GF(p PROJECTION MODEL (X/Z2, Y/Z2) ON PARALLEL HESIAN CURVE USING CRYPTOGRAPHY ELIPTIC CURVE MECHANISM ABSTRACT As a public key cryptography, Elliptic Curve Cryptography (ECC) is well known to be the most secure algorithms that can be used to protect information during the transmission. ECC in its arithmetic computations suffers from modular inversion operation. Modular Inversion is a main arithmetic and very long-time operation that performed by the ECC crypto-processor. The use of projective coordinates to define the Elliptic Curves (EC) instead of affine coordinates replaced the inversion operations by several multiplication operations. Many types of projective coordinates have been proposed for the elliptic curve E: y2 = x3 + ax + b which is defined over a Galois field GF(p) to do EC arithmetic operations where it was found that these several multiplications can be implemented in some parallel fashion to obtain higher performance. In this work, we will study Hessian projective coordinates systems (X/Z2, Y,Z2) over GF (p) to perform ECC doubling operation by using parallel multipliers to obtain maximum parallelism to achieve maximum gain. Keywords: Elliptic Curve Cryptography , Public-Key Cryptosystem , Galois Fields of  Primes GF(p)


Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1389
Author(s):  
Jiwon Lee ◽  
Jihye Kim ◽  
Hyunok Oh

In public key broadcast encryption, anyone can securely transmit a message to a group of receivers such that privileged users can decrypt it. The three important parameters of the broadcast encryption scheme are the length of the ciphertext, the size of private/public key, and the performance of encryption/decryption. It is suggested to decrease them as much as possible; however, it turns out that decreasing one increases the other in most schemes. This paper proposes a new broadcast encryption scheme for tiny Internet of Things (IoT) equipment (BESTIE), minimizing the private key size in each user. In the proposed scheme, the private key size is O(logn), the public key size is O(logn), the encryption time per subset is O(logn), the decryption time is O(logn), and the ciphertext text size is O(r), where n denotes the maximum number of users, and r indicates the number of revoked users. The proposed scheme is the first subset difference-based broadcast encryption scheme to reduce the private key size O(logn) without sacrificing the other parameters. We prove that our proposed scheme is secure under q-Simplified Multi-Exponent Bilinear Diffie-Hellman (q-SMEBDH) in the standard model.


Information ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 75 ◽  
Author(s):  
Yuan Ping ◽  
Baocang Wang ◽  
Shengli Tian ◽  
Jingxian Zhou ◽  
Hui Ma

By introducing an easy knapsack-type problem, a probabilistic knapsack-type public key cryptosystem (PKCHD) is proposed. It uses a Chinese remainder theorem to disguise the easy knapsack sequence. Thence, to recover the trapdoor information, the implicit attacker has to solve at least two hard number-theoretic problems, namely integer factorization and simultaneous Diophantine approximation problems. In PKCHD, the encryption function is nonlinear about the message vector. Under the re-linearization attack model, PKCHD obtains a high density and is secure against the low-density subset sum attacks, and the success probability for an attacker to recover the message vector with a single call to a lattice oracle is negligible. The infeasibilities of other attacks on the proposed PKCHD are also investigated. Meanwhile, it can use the hardest knapsack vector as the public key if its density evaluates the hardness of a knapsack instance. Furthermore, PKCHD only performs quadratic bit operations which confirms the efficiency of encrypting a message and deciphering a given cipher-text.


2021 ◽  
Vol 10 (1) ◽  
pp. 57
Author(s):  
Ms. K. Sudharani ◽  
Dr. N. K. Sakthivel

Certificateless Public Key Cryptography (CL-PKC) scheme is a new standard that combines Identity (ID)-based cryptography and tradi- tional PKC. It yields better security than the ID-based cryptography scheme without requiring digital certificates. In the CL-PKC scheme, as the Key Generation Center (KGC) generates a public key using a partial secret key, the need for authenticating the public key by a trusted third party is avoided. Due to the lack of authentication, the public key associated with the private key of a user may be replaced by anyone. Therefore, the ciphertext cannot be decrypted accurately. To mitigate this issue, an Enhanced Certificateless Proxy Signature (E-CLPS) is proposed to offer high security guarantee and requires minimum computational cost. In this work, the Hackman tool is used for detecting the dictionary attacks in the cloud. From the experimental analysis, it is observed that the proposed E-CLPS scheme yields better Attack Detection Rate, True Positive Rate, True Negative Rate and Minimum False Positives and False Negatives than the existing schemes.   


Sign in / Sign up

Export Citation Format

Share Document