Distributed Marketplaces Using P2P Networks and Public-Key Cryptography

Author(s):  
Alessio Signorini ◽  
Antonio Gulli ◽  
Alberto Maria Segre
2021 ◽  
Author(s):  
Abdolkarim Hajfarajollah Dabbagh

"Due to the lack of a centralized server in “Peer-to-Peer” (P2P) networks, users are responsible for the security of these networks. One of the security issues in P2P networks is the security of the message routing. Messages could be altered or modified by attackers while being routed. The conventional security method to avoid this has been “Public Key Cryptography” (PKC). To avoid the certificate management issue in PKC, “Identity-based Encryption” (IBE) has been suggested in which any arbitrary string could be used as a public key. Since IBE is a computationally expensive method, current proposed IBE-based methods are not effective in the message routing phase in P2P networks and highly affect the performance of message delivery time in these networks. This thesis proposes two IBE-based protocols that can be applied effectively to the message routing phase of structured P2P networks, yet provide a satisfactory message delivery time performance. Both protocols benefit from Identity-based key exchange scheme and, therefore, none of them impose any extra communication on the network to secure message routing. Protocol 1 significantly improves the performance of message delivery time compared to the current IBE-based proposed methods. Protocol 2, which requires nodes to store data, has a performance similar to the situations in which no security measures are applied for message routing."


2021 ◽  
Author(s):  
Abdolkarim Hajfarajollah Dabbagh

"Due to the lack of a centralized server in “Peer-to-Peer” (P2P) networks, users are responsible for the security of these networks. One of the security issues in P2P networks is the security of the message routing. Messages could be altered or modified by attackers while being routed. The conventional security method to avoid this has been “Public Key Cryptography” (PKC). To avoid the certificate management issue in PKC, “Identity-based Encryption” (IBE) has been suggested in which any arbitrary string could be used as a public key. Since IBE is a computationally expensive method, current proposed IBE-based methods are not effective in the message routing phase in P2P networks and highly affect the performance of message delivery time in these networks. This thesis proposes two IBE-based protocols that can be applied effectively to the message routing phase of structured P2P networks, yet provide a satisfactory message delivery time performance. Both protocols benefit from Identity-based key exchange scheme and, therefore, none of them impose any extra communication on the network to secure message routing. Protocol 1 significantly improves the performance of message delivery time compared to the current IBE-based proposed methods. Protocol 2, which requires nodes to store data, has a performance similar to the situations in which no security measures are applied for message routing."


2017 ◽  
Vol 9 (1) ◽  
pp. 30-35
Author(s):  
Sunderi Pranata ◽  
Hargyo Tri Nugroho ◽  
Hirofumi Yamaki

It is known that password itself is not enough for formidable authentication method since it has a lot of vulnerabilities. Multi factor authentication (MFA) is introduced for the next generation for good authentication to address that issue. MFA combines two or more of three principles of good security, “something you know”, “something you have”, and “something you are”. Most MFA mechanisms work as one time passwords (OTP). However, they can still be vulnerable to phishing and MiTM attack. On top of that, OTP can be hard to use as it requires user to input another password given by the device (SMS, token, authenticator). Implemented in small USB U2F device, FIDO U2F delivers easier yet stronger security on authentication process which implements public key cryptography, challenge-response protocol, and phishing and MitM protection.  Index Terms— Authentication protocol, FIDO U2F, Multi factor authentication, OTP


2012 ◽  
Vol 35 (9) ◽  
pp. 1881 ◽  
Author(s):  
Hui-Xian LI ◽  
Xu-Bao CHEN ◽  
Liao-Jun PANG ◽  
Yu-Min WANG

2013 ◽  
Vol 9 (1) ◽  
Author(s):  
Willy Ristanto ◽  
Willy Sudiarto Raharjo ◽  
Antonius Rachmat Chrismanto

Cryptography is a technique for sending secret messages. This research builds an Android-based email client application which implement cryptography with Schmidt-Samoa algorithm, which is classified as a public key cryptography. The algorithm performs encryption and decryption based on exponential and modulus operation on text messages. The application use 512 and 1024 bit keys. Performance measurements is done using text messages with character number variation of 5 – 10.000 characters to obtain the time used for encryption and decryption process. As a result of this research, 99,074% data show that decryption process is faster than encryption process. In 512 bit keys, the system can perform encryption process in 520 - 18.256 miliseconds, and decryption process in 487 - 5.688 miliseconds. In 1024 bit keys, system can perform encryption process in 5626 – 52,142 miliseconds (7.388 times slower than 512 bit keys) and decryption process with time 5463 – 15,808 miliseconds or 8.290 times slower than 512 bit keys.


Author(s):  
Keith M. Martin

In this chapter, we introduce public-key encryption. We first consider the motivation behind the concept of public-key cryptography and introduce the hard problems on which popular public-key encryption schemes are based. We then discuss two of the best-known public-key cryptosystems, RSA and ElGamal. For each of these public-key cryptosystems, we discuss how to set up key pairs and perform basic encryption and decryption. We also identify the basis for security for each of these cryptosystems. We then compare RSA, ElGamal, and elliptic-curve variants of ElGamal from the perspectives of performance and security. Finally, we look at how public-key encryption is used in practice, focusing on the popular use of hybrid encryption.


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