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Lundin, Reine
Publications (10 of 27) Show all publications
Lundin, R. & Lindskog, S. (2013). On Entropy of Selectively Encrypted Bitmap Images using Information Neighborhoods. Journal of Information Assurance and Security, 8(2), 86-96
Open this publication in new window or tab >>On Entropy of Selectively Encrypted Bitmap Images using Information Neighborhoods
2013 (English)In: Journal of Information Assurance and Security, ISSN 1554-1010, E-ISSN 1554-1029, Vol. 8, no 2, p. 86-96Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Atlanta, GA, USA: Dynamic Publishers Incorporation, 2013
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-27187 (URN)
Available from: 2013-05-07 Created: 2013-05-07 Last updated: 2018-01-11Bibliographically approved
Rajiullah, M., Lundin, R., Brunstrom, A. & Lindskog, S. (2013). Performance Analysis and Improvement of PR-SCTP for Small Messages. Computer Networks, 57(18), 3967-3986
Open this publication in new window or tab >>Performance Analysis and Improvement of PR-SCTP for Small Messages
2013 (English)In: Computer Networks, ISSN 1389-1286, Vol. 57, no 18, p. 3967-3986Article in journal (Refereed) Published
Abstract [en]

PR-SCTP, a partially reliable extension of SCTP, provides a flexible QoS trade-off between timeliness and reliability for application traffic. However, the performance of PR-SCTP can be reduced due to certain traffic characteristics and network scenarios. Previously, we proposed a NR-SACK based optimization for PR-SCTP. In this work we extensively evaluate and analyze the performance of PR-SCTP with NR-SACKs using different network scenarios. Moreover, we compare the performance of our NR-SACK based PR-SCTP with existing transport protocols for syslog traffic. In the evaluation, we use real syslog traces from an operational syslog system. The results indicate that NR-SACKs based PR-SCTP significantly improves the overall message transfer delay as compared to SCTP and TCP.

Place, publisher, year, edition, pages
Elsevier: , 2013
Keywords
SCTP, PR-SCTP, NR-SACKs, event logging, performance evaluation
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-14674 (URN)10.1016/j.comnet.2013.09.018 (DOI)000328011900016 ()
Available from: 2012-09-06 Created: 2012-09-06 Last updated: 2018-06-04Bibliographically approved
Lundin, R. & Lindskog, S. (2012). An Investigation of Entropy of Selectively Encrypted Bitmap Images. In: Computational Aspects of Social Networks (CASoN), 2012 Fourth International Conference on: . Paper presented at IAS 2012 - "Innovative Cyber Security: Protecting Nations Beyond Borders" - The 8th Information assurance and security conference, 21-23 November 2012, San Carlos, Brazil (pp. 238-243). IEEE
Open this publication in new window or tab >>An Investigation of Entropy of Selectively Encrypted Bitmap Images
2012 (English)In: Computational Aspects of Social Networks (CASoN), 2012 Fourth International Conference on, IEEE, 2012, p. 238-243Conference paper, Published paper (Refereed)
Abstract [en]

Selective encryption is a concept in which the main goal is to reduce computational cost while providing confidentiality by encrypting only chosen parts of the information to be protected. Previous work on selective encryption has mainly been aimed towards multimedia applications in order to reduce the overhead induced by encryption while still making the information perceptually secure to a desired protection level. This was accomplished by utilizing the fact that different parts of the information have different impacts on our perception senses, i.e., eyes and ears. How computationally secure the information is when using selective encryption has however only briefly been mentioned or rudimentarily analyzed. In this paper, we therefore investigate the security implications of selective encryption by generalizing the work on entropy of selectively encrypted strings to several dimensions and applying it to bitmap images. The generalization is done by constructing information neighborhoods that capture and model information dependencies in several dimensions.

Place, publisher, year, edition, pages
IEEE, 2012
Series
International Conference on Computational Aspects of Social Networks, ISSN 2155-7047
Keywords
security measures, selective encryption, entropy, information neighborhoods, bitmap images
National Category
Computer Engineering
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-15047 (URN)10.1109/CASoN.2012.6412409 (DOI)000314803000041 ()978-1-4673-4793-8 (ISBN)978-1-4673-4792-1 (ISBN)
Conference
IAS 2012 - "Innovative Cyber Security: Protecting Nations Beyond Borders" - The 8th Information assurance and security conference, 21-23 November 2012, San Carlos, Brazil
Available from: 2012-09-28 Created: 2012-09-28 Last updated: 2018-01-12Bibliographically approved
Lundin, R. & Lindskog, S. (2012). Changes in Guesswork over Time in Multi-processor Attacks. Journal of Information Assurance and Security, 7, 145-150
Open this publication in new window or tab >>Changes in Guesswork over Time in Multi-processor Attacks
2012 (English)In: Journal of Information Assurance and Security, ISSN 1554-1010, Vol. 7, p. 145-150Article in journal (Refereed) Published
Abstract [en]

More and more effort is being spent on security improvements in today's computer networking environments. However, due to the nature of computer security there is still a lack of good quantitative assessment methods. Inventing and developing new ways of measuring security are therefore needed in order to more exact describe, assess, and improve security of computer environments. One existing quantitative security measure is guesswork. Guesswork gives the average number of guesses in a brute force attack when breaking an encrypted message. In the current definition of guesswork it is assumed that the attacker uses a single processor when breaking an encrypted message. However, an intelligent and motivated attacker will likely use several processors that can work in parallel to break an encrypted message. This paper formally investigates how guesswork changes over time in multi-processor attacks. The result is applied on three probability distributions, the English alphabet, the geometric, and the truncated geometric to illustrate some behaviors.

Place, publisher, year, edition, pages
Atlanta, GA, USA: Dynamic Publishers Incorporation, 2012
Keywords
computer security, guesswork, multi-processor attacks, quantitative assessment, security measures
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-14094 (URN)10.1109/ISIAS.2011.6122810 (DOI)
Note

Print ISBN 978-1-4577-2154-0

Available from: 2012-06-29 Created: 2012-06-29 Last updated: 2018-01-12Bibliographically approved
Lundin, R. (2012). Guesswork and Entropy as Security Measures for Selective Encryption. (Doctoral dissertation). Karlstad: Karlstad University Press
Open this publication in new window or tab >>Guesswork and Entropy as Security Measures for Selective Encryption
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

More and more effort is being spent on security improvements in today's computer environments, with the aim to achieve an appropriate level of security. However, for small computing devices it might be necessary to reduce the computational cost imposed by security in order to gain reasonable performance and/or energy consumption. To accomplish this selective encryption can be used, which provides confidentiality by only encrypting chosen parts of the information. Previous work on selective encryption has chiefly focused on how to reduce the computational cost while still making the information perceptually secure, but not on how computationally secure the selectively encrypted information is. 

Despite the efforts made and due to the harsh nature of computer security, good quantitative assessment methods for computer security are still lacking. Inventing new ways of measuring security are therefore needed in order to better understand, assess, and improve the security of computer environments. Two proposed probabilistic quantitative security measures are entropy and guesswork. Entropy gives the average number of guesses in an optimal binary search attack, and guesswork gives the average number of guesses in an optimal linear search attack. In information theory, a considerable amount of research has been carried out on entropy and on entropy-based metrics. However, the same does not hold for guesswork.

In this thesis, we evaluate the performance improvement when using the proposed generic selective encryption scheme. We also examine the confidentiality strength of selectively encrypted information by using and adopting entropy and guesswork. Moreover, since guesswork has been less theoretical investigated compared to entropy, we extend guesswork in several ways and investigate some of its behaviors.

Place, publisher, year, edition, pages
Karlstad: Karlstad University Press, 2012. p. 30
Series
Karlstad University Studies, ISSN 1403-8099 ; 2012:36
Keywords
Computer security, security metrics, selective encryption, confidentiality, entropy, guesswork.
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-14032 (URN)978-91-7063-443-7 (ISBN)
Public defence
2012-09-27, 9C 203, Karlstads universitet, 65187 Karlstad, 13:15 (English)
Opponent
Supervisors
Available from: 2012-09-04 Created: 2012-06-28 Last updated: 2018-06-25Bibliographically approved
Rajiullah, M., Lundin, R., Brunström, A. & Lindskog, S. (2011). Data Modeling and Transport of Syslog Messages. In: : . Paper presented at 7th Swedish National Computer Networking Workshop (SNCNW 2011), Linköping, June 13-14, 2011. Linkoping, Sweden: Linköping University
Open this publication in new window or tab >>Data Modeling and Transport of Syslog Messages
2011 (English)Conference paper, Oral presentation only (Refereed)
Place, publisher, year, edition, pages
Linkoping, Sweden: Linköping University, 2011
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10924 (URN)
Conference
7th Swedish National Computer Networking Workshop (SNCNW 2011), Linköping, June 13-14, 2011
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-06-04Bibliographically approved
Lundin, R. & Lindskog, S. (2011). Entropy of Selectively Encrypted Strings. In: Claudio A. Ardagna, Jianying Zhou (Ed.), Claudio A. Ardagna, Jianying Zhou (Ed.), Information Security Theory and Practice: Security and Privacy of Mobile Devices in Wireless Communication. Paper presented at WISTP11 - 5th IFIP WG 11.2 International Workshop in Information Security Theory and Practice, Heraklion, Crete, Greece, June 1-3, 2011 (pp. 234-243). Springer Berlin/Heidelberg
Open this publication in new window or tab >>Entropy of Selectively Encrypted Strings
2011 (English)In: Information Security Theory and Practice: Security and Privacy of Mobile Devices in Wireless Communication / [ed] Claudio A. Ardagna, Jianying Zhou, Springer Berlin/Heidelberg, 2011, p. 234-243Conference paper, Published paper (Refereed)
Abstract [en]

A feature that has become desirable for low-power mobile devices with limited computing and energy resources is the ability to select a security configuration in order to create a trade-off between security and other important parameters such as performance and energy consumption. Selective encryption can be used to create this trade-off by only encrypting chosen units of the information. In this paper, we continue the investigation of the confidentiality implications of selective encryption by applying entropy on a generic selective encryption scheme. By using the concept of run-length vector from run-length encoding theory, an expression is derived for entropy of selectively encrypted strings when the number of encrypted substrings, containing one symbol, and the order of the language change

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2011
Series
Lecture Notes in Computer Science, ISSN 0302-9743 ; 6633
Keywords
computer security, security measures, selective encryption, entropy
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10425 (URN)000306225000016 ()978-3-642-21040-2 (ISBN)
Conference
WISTP11 - 5th IFIP WG 11.2 International Workshop in Information Security Theory and Practice, Heraklion, Crete, Greece, June 1-3, 2011
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
Lundin, R. & Lindskog, S. (2011). Guesswork Changes in Multi-processor Attacks. In: Proceedings of the 7th International Conference on Information Assurance and Security (IAS 2011): . Paper presented at 7th International Conference on Information Assurance and Security (IAS 2011), Melacca, Malaysia, December 5-8 (pp. 145-150). IEEE Press
Open this publication in new window or tab >>Guesswork Changes in Multi-processor Attacks
2011 (English)In: Proceedings of the 7th International Conference on Information Assurance and Security (IAS 2011), IEEE Press, 2011, p. 145-150Conference paper, Published paper (Refereed)
Abstract [en]

More and more effort is being spent on security improvements in today's computer networking environments. However, due to the nature of computer security there is still a lack of good quantitative assessment methods. Inventing and developing new ways of measuring security are therefore needed in order to more exact describe, assess, and improve security of computer environments. One existing quantitative security measure is guesswork. Guesswork gives the average number of guesses in a brute force attack when breaking an encrypted message. In the current definition of guesswork it is assumed that the attacker uses a single processor when breaking an encrypted message. However, an intelligent and motivated attacker will likely use several processors that can work in parallel to break an encrypted message. This paper formally investigates how guesswork changes over time in multi-processor attacks. The result is applied on three probability distributions, the English alphabet, the geometric, and the truncated geometric to illustrate some behaviors.

Place, publisher, year, edition, pages
IEEE Press, 2011
Keywords
Computer security, Computers, Cryptography, Force, Indexes, Probability distribution
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-11893 (URN)10.1109/ISIAS.2011.6122810 (DOI)978-1-4577-2154-0 (ISBN)
Conference
7th International Conference on Information Assurance and Security (IAS 2011), Melacca, Malaysia, December 5-8
Projects
C-BIC fas 2
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Available from: 2012-02-28 Created: 2012-02-28 Last updated: 2018-01-12Bibliographically approved
Lundin, R. & Lindskog, S. (2011). Joint and Conditional Guesswork: Definitions and Implications. Journal of Information Assurance and Security, 6(2), 89-97
Open this publication in new window or tab >>Joint and Conditional Guesswork: Definitions and Implications
2011 (English)In: Journal of Information Assurance and Security, ISSN 1554-1010, Vol. 6, no 2, p. 89-97Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Atlanta, GA, USA: Dynamic Publishers Incorporation, 2011
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10424 (URN)
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
Rajiullah, M., Lundin, R., Lindskog, S. & Brunström, A. (2011). Syslog Performance: Data Modeling and Transport. In: Proceedings of the 3rd International Workshop on Security and Communication Networks (IWSCN 2011): . Paper presented at The 3rd International Workshop on Security and Communication Networks (IWSCN 2011), May 18-20, Gjøvik, Norway (pp. 31-37). Norway: IEEE Press
Open this publication in new window or tab >>Syslog Performance: Data Modeling and Transport
2011 (English)In: Proceedings of the 3rd International Workshop on Security and Communication Networks (IWSCN 2011), Norway: IEEE Press, 2011, p. 31-37Conference paper, Published paper (Refereed)
Abstract [en]

Syslog is one of the basic methods for event logging in computer networks. Log messages that are generated by syslog can be used for a number of purposes, including optimizing system performance, system auditing, and investigating malicious activities in a computer network. Considering all these attractive uses, both timeliness and reliability is needed when syslog messages are transported over a network. The unreliable transport protocol UDP was specified in the original syslog specification; later a reliable transport service based on TCP was also proposed. However, TCP is a costly alternative in terms of delay. In our previous work, we introduced the partially reliable extension of SCTP, PR-SCTP, as a transport service for syslog, trading reliability against timeliness by prioritizing syslog messages. In this work, we first model syslog data using real syslog traces from an operational network. The model is then used as input in the performance evaluation of PR-SCTP. In the experiments, real congestion is introduced in the network by running several competing flows. Although PR-SCTP clearly outperformed TCP and SCTP in our previous work, our present evaluations show that PR-SCTP performance is largely influenced by the syslog data size characteristics

Place, publisher, year, edition, pages
Norway: IEEE Press, 2011
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10922 (URN)
Conference
The 3rd International Workshop on Security and Communication Networks (IWSCN 2011), May 18-20, Gjøvik, Norway
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-06-04Bibliographically approved
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