scholarly journals Implementation of a New Strongly-Asymmetric Algorithm and Its Optimization

Cryptography ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 21
Author(s):  
Koki Jimbo ◽  
Satoshi Iriyama ◽  
Massimo Regoli
Keyword(s):  
General Framework ◽  
Key Agreement ◽  
Public Key ◽  
Security Level ◽  
The Public ◽  
High Speeds ◽  
Diffie Hellman ◽  
New Public ◽  
Public Keys ◽  
Free Parameters

A new public key agreement (PKA) algorithm, called the strongly-asymmetric algorithm (SAA-5), was introduced by Accardi et al. The main differences from the usual PKA algorithms are that Bob has some independent public keys and Alice produces her public key by using some part of the public keys from Bob. Then, the preparation and calculation processes are essentially asymmetric. This algorithms has several free parameters more than the usual symmetric PKA algorithms and the velocity of calculation is largely dependent on the parameters chosen; however, the performance of it has not yet been tested. The purpose of our study was to discuss efficient parameters to share the key with high speeds in SAA-5 and to optimize SAA-5 in terms of calculation speed. To find efficient parameters of SAA-5, we compared the calculation speed with Diffie–Hellman (D-H) while varying values of some parameters under the circumstance where the length of the secret shared key (SSK) was fixed. For optimization, we discuss a more general framework of SAA-5 to find more efficient operations. By fixing the parameters of the framework properly, a new PKA algorithm with the same security level as SAA-5 was produced. The result shows that the calculation speed of the proposed PKA algorithm is faster than D-H, especially for large key lengths. The calculation speed of the proposed PKA algorithm increases linearly as the SSK length increases, whereas D-H increases exponentially.

Key Management

2011 ◽  
pp. 88-113
Author(s):  
Chuan-Kun Wu
Keyword(s):  
Secret Sharing ◽  
Key Management ◽  
Key Agreement ◽  
Public Key ◽  
Key Escrow ◽  
The Public ◽  
Cryptographic Algorithm ◽  
Diffie Hellman ◽  
Public Networks ◽  
Active Attacks

In secure communications, key management is not as simple as metal key management which is supposed to be in a key ring or simply put in a pocket. Suppose Alice wants to transmit some confidential information to Bob over the public networks such as the Internet, Alice could simply encrypt the message using a known cipher such as AES, and then transmit the ciphertext to Bob. However, in order to enable Bob to decrypt the ciphertext to get the original message, in traditional cipher system, Bob needs to have the encryption key. How to let Alice securely and efficiently transmit the encryption key to Bob is a problem of key management. An intuitive approach would be to use a secure channel for the key transmission; this worked in earlier years, but is not a desirable solution in today’s electronic world. Since the invention of public key cryptography, the key management problem with respect to secret key transmission has been solved, which can either employ the Diffie-Hellman key agreement scheme or to use a public key cryptographic algorithm to encrypt the encryption key (which is often known as a session key). This approach is secure against passive attacks, but is vulnerable against active attacks (more precisely the man-in-the-middle attacks). So there must be a way to authenticate the identity of the communication entities. This leads to public key management where the public key infrastructure (PKI) is a typical set of practical protocols, and there is also a set of international standards about PKI. With respect to private key management, it is to prevent keys to be lost or stolen. To prevent a key from being lost, one way is to use the secret sharing, and another is to use the key escrow technique. Both aspects have many research outcomes and practical solutions. With respect to keys being stolen, another practical solution is to use a password to encrypt the key. Hence, there are many password-based security protocols in different applications. This chapter presents a comprehensive description about how each aspect of the key management works. Topics on key management covered by this chapter include key agreement, group-based key agreement and key distribution, the PKI mechanisms, secret sharing, key escrow, password associated key management, and key management in PGP and UMTS systems.

Key Management

2013 ◽  
pp. 728-753
Author(s):  
Chuan-Kun Wu
Keyword(s):  
Secret Sharing ◽  
Key Management ◽  
Key Agreement ◽  
Public Key ◽  
Key Escrow ◽  
The Public ◽  
Cryptographic Algorithm ◽  
Diffie Hellman ◽  
Public Networks ◽  
Active Attacks

In secure communications, key management is not as simple as metal key management which is supposed to be in a key ring or simply put in a pocket. Suppose Alice wants to transmit some confidential information to Bob over the public networks such as the Internet, Alice could simply encrypt the message using a known cipher such as AES, and then transmit the ciphertext to Bob. However, in order to enable Bob to decrypt the ciphertext to get the original message, in traditional cipher system, Bob needs to have the encryption key. How to let Alice securely and efficiently transmit the encryption key to Bob is a problem of key management. An intuitive approach would be to use a secure channel for the key transmission; this worked in earlier years, but is not a desirable solution in today’s electronic world. Since the invention of public key cryptography, the key management problem with respect to secret key transmission has been solved, which can either employ the Diffie-Hellman key agreement scheme or to use a public key cryptographic algorithm to encrypt the encryption key (which is often known as a session key). This approach is secure against passive attacks, but is vulnerable against active attacks (more precisely the man-in-the-middle attacks). So there must be a way to authenticate the identity of the communication entities. This leads to public key management where the public key infrastructure (PKI) is a typical set of practical protocols, and there is also a set of international standards about PKI. With respect to private key management, it is to prevent keys to be lost or stolen. To prevent a key from being lost, one way is to use the secret sharing, and another is to use the key escrow technique. Both aspects have many research outcomes and practical solutions. With respect to keys being stolen, another practical solution is to use a password to encrypt the key. Hence, there are many password-based security protocols in different applications. This chapter presents a comprehensive description about how each aspect of the key management works. Topics on key management covered by this chapter include key agreement, group-based key agreement and key distribution, the PKI mechanisms, secret sharing, key escrow, password associated key management, and key management in PGP and UMTS systems.

scholarly journals BESTIE: Broadcast Encryption Scheme for Tiny IoT Equipment

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1389
Author(s):  
Jiwon Lee ◽  
Jihye Kim ◽  
Hyunok Oh
Keyword(s):  
The Other ◽  
Public Key ◽  
Broadcast Encryption ◽  
Encryption Scheme ◽  
The Public ◽  
Private Key ◽  
Diffie Hellman ◽  
The Standard Model ◽  
Encryption Decryption ◽  
Subset Difference

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.

scholarly journals Survey on Asymmetric Key Cryptographic Algorithms

2020 ◽  
pp. 404-408
Author(s):  
Sabitha S ◽  
Binitha V Nair
Keyword(s):  
Public Key Cryptography ◽  
Public Key ◽  
The Public ◽  
Private Key ◽  
Design And Implementation ◽  
Diffie Hellman ◽  
Encryption And Decryption ◽  
Cryptographic Algorithms ◽  
Symmetric Key ◽  
Symmetric Key Cryptography

Cryptography is an essential and effective method for securing information’s and data. Several symmetric and asymmetric key cryptographic algorithms are used for securing the data. Symmetric key cryptography uses the same key for both encryption and decryption. Asymmetric Key Cryptography also known as public key cryptography uses two different keys – a public key and a private key. The public key is used for encryption and the private key is used for decryption. In this paper, certain asymmetric key algorithms such as RSA, Rabin, Diffie-Hellman, ElGamal and Elliptical curve cryptosystem, their security aspects and the processes involved in design and implementation of these algorithms are examined.

scholarly journals polarRLCE: A New Code-Based Cryptosystem Using Polar Codes

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Jingang Liu ◽  
Yongge Wang ◽  
Zongxiang Yi ◽  
Zhiqiang Lin
Keyword(s):  
Coding Theory ◽  
Public Key ◽  
Security Level ◽  
Polar Codes ◽  
Encryption Scheme ◽  
Cryptographic Primitives ◽  
The Public ◽  
Security Challenges ◽  
High Security Level ◽  
Code Based Cryptography

Security challenges brought about by the upcoming 5G era should be taken seriously. Code-based cryptography leverages difficult problems in coding theory and is one of the main techniques enabling cryptographic primitives in the postquantum scenario. In this work, we propose the first efficient secure scheme based on polar codes (i.e., polarRLCE) which is inspired by the RLCE scheme, a candidate for the NIST postquantum cryptography standardization in the first round. In addition to avoiding some weaknesses of the RLCE scheme, we show that, with the proper choice of parameters, using polar codes, it is possible to design an encryption scheme to achieve the intended security level while retaining a reasonably small public key size. In addition, we also present a KEM version of the polarRLCE scheme that can attain a negligible decryption failure rate within the corresponding security parameters. It is shown that our proposal enjoys an apparent advantage to decrease the public key size, especially on the high-security level.

A nonlinear decomposition attack

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
Vitaliĭ Roman’kov
Keyword(s):  
Key Agreement ◽  
Deterministic Algorithm ◽  
The Public ◽  
Diffie Hellman ◽  
Public Data ◽  
Algorithmic Problems ◽  
New Type ◽  
Nonlinear Decomposition ◽  
Polycyclic Groups ◽  
Agreement Protocols

AbstractThis paper introduces a new type of attack, termed a nonlinear decomposition attack, against two known group-based key agreement protocols, namely, protocol based on extensions of (semi)groups by endomorphisms introduced by Kahrobaei, Shpilrain et al., and the noncommutative Diffie–Hellman protocol introduced by Ko, Lee et al. This attack works efficiently in the case when finitely generated nilpotent (more generally, polycyclic) groups are used as platforms. This attack is based on a deterministic algorithm that finds the secret shared key from the public data in both the protocols under consideration. Furthermore, we show that in this case one can break the schemes without solving the algorithmic problems on which the assumptions are based. The efficacy of the attack depends on the platform group, so it requires a more thorough analysis in each particular case.

scholarly journals Electronic Voting Protocol Using Identity-Based Cryptography

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Gina Gallegos-Garcia ◽  
Horacio Tapia-Recillas
Keyword(s):  
Key Agreement ◽  
Public Key Cryptography ◽  
Public Key ◽  
Electronic Voting ◽  
Certification Authority ◽  
Public Keys ◽  
Core Components ◽  
Identity Based ◽  
High Flexibility ◽  
Agreement Protocols

Electronic voting protocols proposed to date meet their properties based on Public Key Cryptography (PKC), which offers high flexibility through key agreement protocols and authentication mechanisms. However, when PKC is used, it is necessary to implement Certification Authority (CA) to provide certificates which bind public keys to entities and enable verification of such public key bindings. Consequently, the components of the protocol increase notably. An alternative is to use Identity-Based Encryption (IBE). With this kind of cryptography, it is possible to have all the benefits offered by PKC, without neither the need of certificates nor all the core components of a Public Key Infrastructure (PKI). Considering the aforementioned, in this paper we propose an electronic voting protocol, which meets the privacy and robustness properties by using bilinear maps.

scholarly journals Analisis dan Implementasi Algoritma Asimetris Dual Modulus RSA (DM-RSA) pada Aplikasi Chat

2021 ◽  
Vol 5 (4) ◽  
pp. 768-773
Author(s):  
Aminudin ◽  
Ilyas Nuryasin
Keyword(s):  
Prime Numbers ◽  
Public Key ◽  
Generation Process ◽  
Key Generation ◽  
The Public ◽  
Asymmetric Model ◽  
Rsa Algorithm ◽  
Private Key ◽  
Public Keys ◽  
Cryptographic Algorithms

The RSA algorithm is one of the cryptographic algorithms with an asymmetric model where the algorithm has two keys, namely the public key and the private key. However, as time goes on, these algorithms are increasingly exposed to security holes and make this algorithm vulnerable to being hacked by people who do not have authority. The vulnerability stems from the algorithm's public keys (e and n). The strength of the RSA algorithm is based on the difficulty of factoring two prime numbers that are generated during the key generation process, if these values ​​can be known using certain methods, the public key and private key values ​​will be found. Therefore, there are many studies that improvise the RSA algorithm, one of which is the Dual Modulus RSA (DM-RSA) algorithm. The algorithm uses four prime numbers which produce 2 modulus and 4 keys (2 public keys and 2 private keys). From the results of the Kraitchik factorization test, it was found that the DM-RSA algorithm was proven to be more resistant up to 2 times or even more than the standard RSA algorithm. This is evidenced by the fact that the value of n is 24 bits, the RSA algorithm can last up to 63204 ms (1 minute 22 seconds) while the Dual Modulus RSA algorithm lasts up to 248494123 ms (142 minutes 47 seconds).  

scholarly journals A Certificateless Noninteractive Key Exchange Protocol with Provable Security

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xuefei Cao ◽  
Lanjun Dang ◽  
Yingzi Luan ◽  
Wei You
Keyword(s):  
Random Oracle Model ◽  
Random Oracle ◽  
Key Exchange ◽  
Public Key ◽  
Communication Overhead ◽  
Key Exchange Protocol ◽  
The Public ◽  
Diffie Hellman ◽  
Message Exchange ◽  
Certificateless Public Key Cryptosystem

In this paper, we propose a certificateless noninteractive key exchange protocol. No message exchange is required in the protocol, and this feature will facilitate the applications where the communication overhead matters, for example, the communications between the satellites and the earth. The public key certificate is removed as well as the key escrow problem using the certificateless public key cryptosystem. The security of the protocol rests on the bilinear Diffie–Hellman problem, and it could be proved in the random oracle model. Compared with previous protocols, the new protocol reduces the running time by at least 33.0%.

Sign in / Sign up

Export Citation Format

Share Document