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symmetric-cryptography
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Cryptanalysis of Lightweight Block Ciphers
, M.Sc. Thesis Sharif University of Technology ; Aref, Mohammad Reza (Supervisor) ; Salmasizadeh, Mahmoud (Co-Advisor)
Abstract
Lightweight cryptography is a branch of cryptography science which is expanded in response of security need in pervasive and lightweight systems (such as RFID systems and wireless sensor networks) in the last decade. In general, the significant challenges in designing lightweight ciphers can be attributed to three essential parameters: security, cost, and performance. Hence the main goal in designing new lightweight ciphers is to develop innovative and atypical structures in order to have a cipher with a small footprint, sufficient speed, reduced power consumption, while remaining sufficiently secure. Due to lack of proper ciphers that are both efficient and secure for constrained...
A secure self-synchronized stream cipher
, Article Computer Journal ; Volume 61, Issue 8 , August , 2018 , Pages 1182-1201 ; 00104620 (ISSN) ; Mohebbipoor, F ; Sharif University of Technology
Oxford University Press
2018
Abstract
We follow two main objectives in this article. On the one hand, we introduce a security model called LORBACPA+ for self-synchronized stream ciphers which is stronger than the blockwise LOR-IND-CPA, where we show that standard constructions as delayed CBC or similar existing self-synchronized modes of operation are not secure in this stronger model. Then, on the other hand, following contributions of Millérioux et al., we introduce a new self-synchronized stream cipher and prove its security in LORBACPA+ model. © The British Computer Society 2018. All rights reserved
Cryptanalysis of Two Authenticated Encryption Schemes Pr∅st and NORX Introduced in CAESAR
, M.Sc. Thesis Sharif University of Technology ; Aref, Mohammad Reza (Supervisor) ; Mohajeri, Javad (Co-Advisor)
Abstract
The goal of authenticated encryption is to ensure confidentiality, integrity and authenti-cation of the messages simultaneously. The anouncement of CAESAR comptetition has attracted esearchers’ attention to this branch of symmetric cryptography, since 2014. 57 schemes have been introduced as the first round candidates of this competition, from which 29 where selected as second round candidates. Cryptanalysis of these schemes needs a lot of collective effort. In this thesis after describing preliminaries of authen- ticated encryption, general structure of the schemes and their reported cryptanalysis is reviewed. Then, the details of Pr∅st family of authenticated encryption, which is one of...
Improved user identity confidentiality for UMTS mobile networks
, Article ECUMN 2007: Fourth European Conference on Universal Multiservice Networks, Toulouse, 14 February 2007 through 16 February 2007 ; 2007 , Pages 401-409 ; 076952768X (ISBN); 9780769527680 (ISBN) ; Asadpour, M ; Jalili, R ; Sharif University of Technology
2007
Abstract
In UMTS mobile networks, there are some circumstances that the International Mobile Subscriber Identity (IMSI) of a user is conveyed in clear-text over the radio interface. Such situations violate the anonymity of users. In this paper, we introduce an Improved User Identity Confidentiality (IUIC) mechanism which attempts to avoid the drawback and makes users more anonymous. We give the role of IMSI to anonymous tickets in such a way that IMSI is never exposed on the radio interface or over any other link. Our IUIC mechanism, employs symmetric cryptography based on the existing network access security features of UMTS. Its implementation, security, and performance issues are also considered....
SEAODV: Secure efficient AODV routing protocol for MANETs networks
, Article ACM International Conference Proceeding Series, 24 November 2009 through 26 November 2009, Seoul ; Volume 403 , 2009 , Pages 940-944 ; 9781605587103 (ISBN) ; Movaghar, A ; Safi, S. M ; Sharif University of Technology
Abstract
Secure routing is one of the most important topics in the wireless MANETs networks. MANETs networks don't have a central infrastructure for the management of routing in the networks. Each node independently routes and sends packets, so many attacks such as forging, modifying, and denial of service (DoS), Occur in these networks. In this paper, we present the new protocol, SEAODV; Secure Efficient Ad-hoc on Demand Routing Protocol for MANETs networks. SEAODV is based on the AODV algorithm and in comparison with existing secure AODV protocols such as SAODV, ARAN and SEAR have improved security and performances. SEAODV uses HEAP authentication Scheme with symmetric cryptography and one-way hash...
Virtual address space mapping for IP auto-configuration in MANET with security capability
, Article Proceedings of the 2008 International Conference on Advanced Infocomm Technology, ICAIT '08, 29 July 2008 through 31 July 2008, Shenzhen ; 2008 ; 9781605580883 (ISBN) ; Tajamolian, M ; Dehghan, M ; Mousavi, R ; Sharif University of Technology
2008
Abstract
Mobile Ad Hoc Networks (MANETs) are networks with selforganizing capabilities and without a fixed infrastructure. Wireless nodes communicate among themselves using multi-hop radio relaying, without requiring the packets to pass through a central access point or a base station. In a highly mobile and infrastructure-less scenario, pre-configuration of addresses is not possible. Therefore node addresses need to be configured dynamically with minimum delay and packet loss. Existing solutions for IP address auto-configuration do not address security issues. In this paper we propose a secure address autoconfiguration for Mobile Ad hoc Networks (MANET) based on Virtual Address Space Mapping [1]....