17 research outputs found

    On the Entropy of Arcfour Keys

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    This paper is a copy of IBM Research Report RZ 3019 published in 1998, which was a study of some issues related to keys of Arcfour. At the time of writing Arcfour was the common pseudonym used for RC4. Quite of a few of the results in the paper have now been superseded. We have submitted this paper to the IACR eprint archive mainly for reference purposes, since IBM research reports are not indexed in general by Google and other search engines

    Review on DNA Cryptography

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    Cryptography is the science that secures data and communication over the network by applying mathematics and logic to design strong encryption methods. In the modern era of e-business and e-commerce the protection of confidentiality, integrity and availability (CIA triad) of stored information as well as of transmitted data is very crucial. DNA molecules, having the capacity to store, process and transmit information, inspires the idea of DNA cryptography. This combination of the chemical characteristics of biological DNA sequences and classical cryptography ensures the non-vulnerable transmission of data. In this paper we have reviewed the present state of art of DNA cryptography.Comment: 31 pages, 12 figures, 6 table

    Wireless LAN security.

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    Chan Pak To Patrick.Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.Includes bibliographical references (leaves 82-86).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.iiiContents --- p.ivList of Figures --- p.viiList of Tables --- p.viiiChapter 1 --- Introduction --- p.1Chapter 1.1 --- Motivation --- p.1Chapter 1.2 --- The Problems --- p.3Chapter 1.3 --- My Contribution --- p.4Chapter 1.4 --- Thesis Organization --- p.5Chapter 2 --- Wireless LAN Security Model --- p.6Chapter 2.1 --- Preliminary Definitions on WLAN --- p.6Chapter 2.2 --- Security Model --- p.7Chapter 2.2.1 --- Security Attributes --- p.7Chapter 2.2.2 --- Security Threats in WLAN --- p.8Chapter 2.2.3 --- Attacks on Authentication Scheme --- p.10Chapter 2.2.4 --- Attacks on Keys --- p.10Chapter 2.3 --- Desired Properties of WLAN Authentication --- p.11Chapter 2.3.1 --- Security Requirements of WLAN Authentication --- p.11Chapter 2.3.2 --- Security Requirements of Session Keys --- p.12Chapter 2.3.3 --- Other Desired Properties of WLAN Authentication --- p.12Chapter 3 --- Cryptography --- p.14Chapter 3.1 --- Overview on Cryptography --- p.14Chapter 3.2 --- Symmetric-key Encryption --- p.15Chapter 3.2.1 --- Data Encryption Standard (DES) --- p.15Chapter 3.2.2 --- Advanced Encryption Standard (AES) --- p.15Chapter 3.2.3 --- RC4 --- p.16Chapter 3.3 --- Public-key Cryptography --- p.16Chapter 3.3.1 --- RSA Problem and Related Encryption Schemes --- p.17Chapter 3.3.2 --- Discrete Logarithm Problem and Related Encryption Schemes --- p.18Chapter 3.3.3 --- Elliptic Curve Cryptosystems --- p.19Chapter 3.3.4 --- Digital Signature --- p.19Chapter 3.4 --- Public Key Infrastructure --- p.20Chapter 3.5 --- Hash Functions and Message Authentication Code --- p.21Chapter 3.5.1 --- SHA-256 --- p.22Chapter 3.5.2 --- Message Authentication Code --- p.22Chapter 3.6 --- Entity Authentication --- p.23Chapter 3.6.1 --- ISO/IEC 9798-4 Three-pass Mutual --- p.23Chapter 3.6.2 --- ISO/IEC 9798-4 One-pass Unilateral --- p.24Chapter 3.7 --- Key Establishment --- p.24Chapter 3.7.1 --- Diffie-Hellman Key Exchange --- p.24Chapter 3.7.2 --- Station-to-Station Protocol --- p.25Chapter 3.8 --- Identity-Based Cryptography --- p.25Chapter 3.8.1 --- The Boneh-Franklin Encryption Scheme --- p.26Chapter 3.8.2 --- Au and Wei's Identification Scheme and Signature Scheme --- p.27Chapter 4 --- Basics of WLAN Security and WEP --- p.29Chapter 4.1 --- Basics of WLAN Security --- p.29Chapter 4.1.1 --- "Overview on ""Old"" WLAN Security" --- p.29Chapter 4.1.2 --- Some Basic Security Measures --- p.29Chapter 4.1.3 --- Virtual Private Network (VPN) --- p.30Chapter 4.2 --- WEP --- p.31Chapter 4.2.1 --- Overview on Wired Equivalent Privacy (WEP) --- p.31Chapter 4.2.2 --- Security Analysis on WEP --- p.33Chapter 5 --- IEEE 802.11i --- p.38Chapter 5.1 --- Overview on IEEE 802.11i and RSN --- p.38Chapter 5.2 --- IEEE 802.1X Access Control in IEEE 802.11i --- p.39Chapter 5.2.1 --- Participants --- p.39Chapter 5.2.2 --- Port-based Access Control --- p.40Chapter 5.2.3 --- EAP and EAPOL --- p.40Chapter 5.2.4 --- RADIUS --- p.41Chapter 5.2.5 --- Authentication Message Exchange --- p.41Chapter 5.2.6 --- Security Analysis --- p.41Chapter 5.3 --- RSN Key Management --- p.43Chapter 5.3.1 --- RSN Pairwise Key Hierarchy --- p.43Chapter 5.3.2 --- RSN Group Key Hierarchy --- p.43Chapter 5.3.3 --- Four-way Handshake and Group Key Handshake --- p.44Chapter 5.4 --- RSN Encryption and Data Integrity --- p.45Chapter 5.4.1 --- TKIP --- p.45Chapter 5.4.2 --- CCMP --- p.46Chapter 5.5 --- Upper Layer Authentication Protocols --- p.47Chapter 5.5.1 --- Overview on the Upper Layer Authentication --- p.47Chapter 5.5.2 --- EAP-TLS --- p.48Chapter 5.5.3 --- Other Popular ULA Protocols --- p.50Chapter 6 --- Proposed IEEE 802.11i Authentication Scheme --- p.52Chapter 6.1 --- Proposed Protocol --- p.52Chapter 6.1.1 --- Overview --- p.52Chapter 6.1.2 --- The AUTHENTICATE Protocol --- p.56Chapter 6.1.3 --- The RECONNECT Protocol --- p.59Chapter 6.1.4 --- Packet Format --- p.61Chapter 6.1.5 --- Ciphersuites Negotiation --- p.64Chapter 6.1.6 --- Delegation --- p.64Chapter 6.1.7 --- Identity Privacy --- p.68Chapter 6.2 --- Security Considerations --- p.68Chapter 6.2.1 --- Security of the AUTHENTICATE protocol --- p.68Chapter 6.2.2 --- Security of the RECONNECT protocol --- p.69Chapter 6.2.3 --- Security of Key Derivation --- p.70Chapter 6.2.4 --- EAP Security Claims and EAP Methods Requirements --- p.72Chapter 6.3 --- Efficiency Analysis --- p.76Chapter 6.3.1 --- Overview --- p.76Chapter 6.3.2 --- Bandwidth Performance --- p.76Chapter 6.3.3 --- Computation Speed --- p.76Chapter 7 --- Conclusion --- p.79Chapter 7.1 --- Summary --- p.79Chapter 7.2 --- Future Work --- p.80Bibliography --- p.8

    Ongoing Research Areas in Symmetric Cryptography

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    This report is a deliverable for the ECRYPT European network of excellence in cryptology. It gives a brief summary of some of the research trends in symmetric cryptography at the time of writing. The following aspects of symmetric cryptography are investigated in this report: • the status of work with regards to different types of symmetric algorithms, including block ciphers, stream ciphers, hash functions and MAC algorithms (Section 1); • the recently proposed algebraic attacks on symmetric primitives (Section 2); • the design criteria for symmetric ciphers (Section 3); • the provable properties of symmetric primitives (Section 4); • the major industrial needs in the area of symmetric cryptography (Section 5)

    The M3dcrypt Password Hashing Function

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    M3dcrypt is a password hashing function built around the Advanced Encryption Standard (AES) algorithm and the arcfour pseudorandom function. It uses up to 256-bit pseudorandom salt values and supports 48-byte passwords

    D.STVL.9 - Ongoing Research Areas in Symmetric Cryptography

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    This report gives a brief summary of some of the research trends in symmetric cryptography at the time of writing (2008). The following aspects of symmetric cryptography are investigated in this report: • the status of work with regards to different types of symmetric algorithms, including block ciphers, stream ciphers, hash functions and MAC algorithms (Section 1); • the algebraic attacks on symmetric primitives (Section 2); • the design criteria for symmetric ciphers (Section 3); • the provable properties of symmetric primitives (Section 4); • the major industrial needs in the area of symmetric cryptography (Section 5)

    Design implementation and analysis of a dynamic cryptography algorithm with applications

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    Cryptographers need to provide the world with a new encryption standard. DES, the major encryption algorithm for the past fifteen years, is nearing the end of its useful life. Its 56-bit key size is vulnerable to a brute-force attack on powerful microprocessors and recent advances in linear cryptanalysis and differential cryptanalysis indicate that DES is vulnerable to other attacks as well. A more recent attack called XSL, proposes a new attack against AES and Serpent. The attack depends much more critically on the complexity of the nonlinear components than on the number of rounds. Ciphers with small S-boxes and simple structures are particularly vulnerable. Serpent has small S-boxes and a simple structure. AES has larger S-boxes, but a very simple algebraic description. If the attack is proven to be correct, cryptographers predict it to break AES with a 2; 80 complexity, over the coming years; Many of the other unbroken algorithms---Khufu, REDOC II, and IDEA---are protected by patents. RC2 is broken. The U.S. government has declassified the Skipjack algorithm in the Clipper and Capstone chips

    Spritz---a spongy RC4-like stream cipher and hash function.

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    This paper reconsiders the design of the stream cipher RC4, and proposes an improved variant, which we call ``Spritz\u27\u27 (since the output comes in fine drops rather than big blocks.) Our work leverages the considerable cryptanalytic work done on the original RC4 and its proposed variants. It also uses simulations extensively to search for biases and to guide the selection of intermediate expressions. We estimate that Spritz can produce output with about 24 cycles/byte of computation. Furthermore, our statistical tests suggest that about 2812^{81} bytes of output are needed before one can reasonably distinguish Spritz output from random output; this is a marked improvement over RC4. [Footnote: However, see Appendix F for references to more recent work that suggest that our estimates of the work required to break Spritz may be optimistic.] In addition, we formulate Spritz as a ``sponge (or sponge-like) function,\u27\u27 (see Bertoni et al.), which can ``Absorb\u27\u27 new data at any time, and from which one can ``Squeeze\u27\u27 pseudorandom output sequences of arbitrary length. Spritz can thus be easily adapted for use as a cryptographic hash function, an encryption algorithm, or a message-authentication code generator. (However, in hash-function mode, Spritz is rather slow.

    Developing a Systematic Process for Mobile Surveying and Analysis of WLAN security

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    Wireless Local Area Network (WLAN), familiarly known as Wi-Fi, is one of the most used wireless networking technologies. WLANs have rapidly grown in popularity since the release of the original IEEE 802.11 WLAN standard in 1997. We are using our beloved wireless internet connection for everything and are connecting more and more devices into our wireless networks in every form imaginable. As the number of wireless network devices keeps increasing, so does the importance of wireless network security. During its now over twenty-year life cycle, a multitude of various security measures and protocols have been introduced into WLAN connections to keep our wireless communication secure. The most notable security measures presented in the 802.11 standard have been the encryption protocols Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access (WPA). Both encryption protocols have had their share of flaws and vulnerabilities, some of them so severe that the use of WEP and the first generation of the WPA protocol have been deemed irredeemably broken and unfit to be used for WLAN encryption. Even though the aforementioned encryption protocols have been long since deemed fatally broken and insecure, research shows that both can still be found in use today. The purpose of this Master’s Thesis is to develop a process for surveying wireless local area networks and to survey the current state of WLAN security in Finland. The goal has been to develop a WLAN surveying process that would at the same time be efficient, scalable, and easily replicable. The purpose of the survey is to determine to what extent are the deprecated encryption protocols used in Finland. Furthermore, we want to find out in what state is WLAN security currently in Finland by observing the use of other WLAN security practices. The survey process presented in this work is based on a WLAN scanning method called Wardriving. Despite its intimidating name, wardriving is simply a form of passive wireless network scanning. Passive wireless network scanning is used for collecting information about the surrounding wireless networks by listening to the messages broadcasted by wireless network devices. To collect our research data, we conducted wardriving surveys on three separate occasions between the spring of 2019 and early spring of 2020, in a typical medium-sized Finnish city. Our survey results show that 2.2% out of the located networks used insecure encryption protocols and 9.2% of the located networks did not use any encryption protocol. While the percentage of insecure networks is moderately low, we observed during our study that private consumers are reluctant to change the factory-set default settings of their wireless network devices, possibly exposing them to other security threats

    WiFi Miner: An online apriori and sensor based wireless network Intrusion Detection System

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    This thesis proposes an Intrusion Detection System, WiFi Miner, which applies an infrequent pattern association rule mining Apriori technique to wireless network packets captured through hardware sensors for purposes of real time detection of intrusive or anomalous packets. Contributions of the proposed system includes effectively adapting an efficient data mining association rule technique to important problem of intrusion detection in a wireless network environment using hardware sensors, providing a solution that eliminates the need for hard-to-obtain training data in this environment, providing increased intrusion detection rate and reduction of false alarms. The proposed system, WiFi Miner, solution approach is to find frequent and infrequent patterns on pre-processed wireless connection records using infrequent pattern finding Apriori algorithm also proposed by this thesis. The proposed Online Apriori-Infrequent algorithm improves the join and prune step of the traditional Apriori algorithm with a rule that avoids joining itemsets not likely to produce frequent itemsets as their results, thereby improving efficiency and run times significantly. A positive anomaly score is assigned to each packet (record) for each infrequent pattern found while a negative anomaly score is assigned for each frequent pattern found. So, a record with final positive anomaly score is considered as anomaly based on the presence of more infrequent patterns than frequent patterns found
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