tag:blogger.com,1999:blog-71577131180016806852012-02-16T12:32:17.170+02:00mostly on crypto, games and other stuff I like ...Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.comBlogger371100tag:blogger.com,1999:blog-7157713118001680685.post-29675975284875546042011-12-26T23:23:00.001+02:002011-12-26T23:26:00.427+02:00

My recent paper presented at Artificial Intelligence and Security Workshop, Chicago, 2011.Abstract:A binary de Bruijn sequence of order n is a cyclic sequence of period 2n, in which each n-bit pattern appears exactly once. These sequences are commonly used in random number generation and symmetric key cryptography particularly in stream cipher design, mainly due to their good statistical

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-1322857726312467232010-12-19T08:43:00.003+02:002010-12-19T09:00:57.134+02:00

NIST announced the SHA-3 Finalists on December 9, 2010. Congratulations to the designers of Blake, Grostl, JH, Keccak and Skein. Any comments?

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com3tag:blogger.com,1999:blog-7157713118001680685.post-23269188739349239332010-10-01T04:47:00.004+03:002010-12-20T05:07:38.151+02:00

Our latest paper on near-collision resistance on some of the SHA-3 candidates; Blake, Fugue, JH and Hamsi is accepted for Indocrypt 2010. Abstract :A hash function is near-collision resistant, if it is hard to find two messages with hash values that differ in only a small number of bits. In this study, we use hill climbing methods to evaluate the near-collision resistance of some of the second

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-41658093755712735102010-08-14T04:15:00.003+03:002010-08-14T04:22:16.492+03:00

Hamsi is a family of cryptographic hash functions designed by Ozgul Kucuk. It is one of the second round candidates. The iteration mode of Hamsi is based on the `Concatenate-Permute-Truncate` design strategy. We recently published a paper titled "Message Recovery and Pseudo-preimage Attacks on the Compression Function of Hamsi-256" at PROGRESS IN CRYPTOLOGY – LATINCRYPT 2010. Abstract: Hamsi is

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-29336386000857567242010-08-14T04:12:00.003+03:002010-08-14T04:22:53.261+03:00

Our recent paper on the feedback functions of maximum length NFSRs is published in IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Science. Abstract: Feedback shift registers are basic building blocks for many cryptographic primitives. Due to the insecurities of Linear Feedback Shift Register (LFSR) based systems, the use of Nonlinear Feedback Shift Registers (NFSRs

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-23914476606515851802009-12-20T19:08:00.003+02:002009-12-20T20:12:16.963+02:00

Here is a book on optimization problems. It is going to be available in April 2010. The book includes a chapter with title "An evolutionary approach for the TSP and the TSP with Backhauls" written by H. Sural, N.E. Ozdemirel, I. Onder and myself.If you want more details from Springer web page:"In modern science and engineering, laboratory experiments are replaced by high fidelity and

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-58568663860708338412009-05-19T11:05:00.004+03:002009-05-20T09:53:10.224+03:00

My cell phone does not support Skymap for the moment, but I really liked the idea of moving your phone to find a specific star. Well of course I don't need SkyMap to spot Orion or the polar star. But might be useful to find some of the constellations and planets.Here is its one minute demo.:

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-32865907014160342532009-05-18T23:42:00.006+03:002009-05-20T09:54:15.451+03:00

Nowadays, I spend most of my time studying on Nonlinear Feedback Shift Registers (NFSRs). Especially the ones with Maximum period. A feedback shift register is a device that shifts its contents into adjacent positions within the register and fills the position on the other end with a new value generated by the feedback function. If the feedback function is linear, everything is easy! :)But when

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com10tag:blogger.com,1999:blog-7157713118001680685.post-45427603326701588362009-05-18T23:12:00.007+03:002009-05-20T09:53:10.224+03:00

It was officially launced today, and I had some chance to 'play' with it. I am impressed by a few of its features. One of them is when you input "ATTAGCGTTCAA", Wolfram Alpha recognizes it as a genome sequence and outputs some matches in human genome. :) Isn't that fun ? I believe it is going to be a serious competitor to Wikipedia.There are also a few crypto related features. You can hash a

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-53139252480693938802009-04-13T23:37:00.002+03:002009-05-20T09:54:41.262+03:00

Real Analysts do it continuously.Complex Analysts do it conformally and entirely.Point Set Topologists do it openly, but compactly.Combinatorists do it discretely.Statisticians do it robustly.Probabilists, we're not sure if they do it.Logicians do it consistently.Differential Topologists do it smoothly.Algebraic Topologists do it manifold ways.Algebraic Geometers scheme to do it without

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com2tag:blogger.com,1999:blog-7157713118001680685.post-15847114269987879122009-04-08T23:26:00.005+03:002009-05-20T09:54:41.262+03:00

I recently read the book "Cosmicomics" by Italo Calvino. It is by far the funniest book I have ever read. Book includes many short scientific stories.The one I like the most is called "The Light Years". One day Qfwfq (our hero) looks at stars and sees someone with a sign saying "I saw you" from 100,000,000 light years away and checks his diary to find out what he was doing that day. Then the

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-13757939663857180792008-11-28T22:08:00.006+02:002009-05-20T09:54:41.262+03:00

I am a fun of the bunny suicide pictures by Andy Riley. Here are the ones I like most, click for more.

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-1771516815274852722008-11-27T23:06:00.003+02:002008-11-27T23:13:09.725+02:00

This is a new book by Koc, Cetin Kaya (Ed.) written for graduate students and researchers in cryptography and engineers working in the industry.Here are some details from the Springer web page: Cryptographic Engineering covers the theory and practice of engineering of cryptographic systems, including encryption and decryption engines, digital signature and authentication systems, true random

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-28033399358644074242008-11-22T23:39:00.003+02:002008-11-22T23:44:40.376+02:00

This is another animation that I enjoyed, the story, the colors and everything. It is about a fat panda who wants to be a kung fu fighter and "accidently" becomes one. Here are some quotes from the movie."I just ate, so I'm still digesting, so my kung fu may not be as good as later on""Yesterday is history, tomorrow is a mystery, but today is a gift. That is why it is called the present""One

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-25549618088670859712008-11-18T23:32:00.003+02:002008-11-22T23:44:47.808+02:00

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-65195104428611512412008-11-18T22:54:00.012+02:002008-11-18T23:26:09.309+02:00

"The Bedroom at Arles" by Vincent van Gogh, 1888 in Musee d'Orsay, Paris "Palacio Almi" by Xul Solar, 1932 in Museo Xul Solar, Buenos Aires"The Scream" by Edvard Munch, 1893 in National Gallery, Oslo"Man in a red turban" by Jan van Eyck, 1433 in National Gallery London"Wanderer above the Sea of Fog" by Caspar David Friedrich, 1818 in Hamburger Kunsthalle, Hamburg

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com1tag:blogger.com,1999:blog-7157713118001680685.post-38577172264079331042008-11-12T23:28:00.002+02:002008-11-12T23:39:43.156+02:00

Although I am not one of those cat-lovers, I really liked the Japanese animation "The Cat Returns" by Hiroyuki Morita. It is a story of a young quiet and shy girl Haru. One day, she rescues a cat, which happened to be the prince of cat kingdom, from being hit by a truck. Then, she receives thank you gifts like mice and is offered to marry the cat prince. She gets confused and begins to think that

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-12560278655140032372008-10-22T08:11:00.003+03:002008-10-23T21:47:16.741+03:00

This summer, METU hosted the CIMPA-UNESCO-TUBITAK summer school on "Codes over Rings". I was able to follow some of the lectures. There were about 40 participants from Germany, India, Irak, Iran, Jordan, Ivory Coast, Philippines and Tunisia. In May 18-30 2009, there will be another summer school on cryptography in Morrocco. The deadline for registration is january 31, 2009. Here is the link.

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-12308414125773040032008-10-18T16:20:00.002+03:002008-10-23T21:45:53.659+03:00

Bu donem Ankara'da olmayacagim icin boks anteremanlarini kaciracagima cok uzuluyorum. Ama katilmak isteyenler icin link vereyim. Sayfa tam olarak bitmemis ama iletisim detaylari mevcut. 'Siddetle' tavsiye ederim. Cok keyifli. :))

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-45449614946609258672008-10-15T09:27:00.004+03:002008-10-15T09:45:15.923+03:00

Here is a picture taken by Bulent ozturk from my graduation in June 2008.

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-79629632695210270522008-10-02T11:22:00.002+03:002008-10-02T11:34:57.003+03:00

Her sene sabirsizlikla bekledigim zeka oyunlari yarismasinin eleme sinav sorulari aciklandi. Bazi sorular beni hayal kirikligina ugratsada, gene de ugrasmaya deger. Cevaplari gondermek icin son tarih 24 Ekim 2008. Sorulara ulasmak icin bu linki kullanabilirsiniz.

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com1tag:blogger.com,1999:blog-7157713118001680685.post-32112281579679344442008-10-02T11:12:00.003+03:002008-10-23T21:47:16.741+03:00

This is the Call for papers of the 3rd Information Security and Cryptology Conference in Ankara, Turkey. This year the main topic of the International Information Security and Cryptology Conference is “Homeland Security”. We are hoping that this conference will be a platform to discuss information security, to present new approaches and applications, and to inform wider audiences about security

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com1tag:blogger.com,1999:blog-7157713118001680685.post-54307949642992263882008-09-29T23:03:00.000+03:002008-09-29T23:12:36.250+03:00

Recently we have celebrated the 10th birthday of Google. As its birthday present, Google wants our ideas that can change the world by helping as many people as possible. Google have launched a new project Project 10^100. By October 20, you can submit our idea. For more info, check this web page

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-86767497795225684452008-09-29T22:34:00.000+03:002008-10-23T21:47:16.741+03:00

A Mersenne prime is a prime of the form 2^{P}-1. First Mersenne primes are 3, 7, 31, 127. Recently, researchers have discovered the two largest known Mersenne primes with 12,978,189 and 11,185,272 digits. The larger number qualifies for a $100,000 research award. If you want to make some money, you can go for the 47th Mersenne prime. For more information, check out the webpage of GIMPS- Great

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-10217148213070371792008-08-28T19:46:00.000+03:002009-05-20T09:53:49.361+03:00

A very nice video from "The Klein Four Group". It is available in Youtube. The lyrics are; The path of love is never smoothBut mine's continuous for youaYou're the upper bound in the chains of my heartYou're my Axiom of Choice, you know it's trueBut lately our relation's not so well-definedAnd I just can't function without youI'll prove my proposition and I'm sure you'll findWe're a finite simple

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-44386869231602801872008-08-11T22:21:00.001+03:002010-08-14T04:56:05.422+03:00

The paper is a joint work with Ali Doganaksoy and Serdar Boztas. It is going to be presented in SETA08 (SEquences and Their Application) Conference in Lexington, Kentucky.Abstract:Statistical randomness testing has significant importance in analyzing the quality of random number generators. In this study, we focus on the independence of randomness tests and its effect on the coverage of test

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Cryptanalysis is the study of deciphering the encrypted message without knowing the secret key. A trivial attack to any cryptosystem is to try every possible key until the correct one is recovered. If the key size is k, attacker has to try 2^k keys in the worst case, and on the average 2^{k-1} keys. To detect the correct key, a plaintext/ciphertext pair is needed. However, if the plaintext

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-11766055986808457262008-08-11T21:19:00.000+03:002010-08-14T04:56:24.442+03:00

This state-of-the-art survey presents the outcome of the eSTREAM Project, which was launched in 2004 as part of ECRYPT, the European Network of Excellence in Cryptology (EU Framework VI).The goal of eSTREAM was to promote the design of new stream ciphers with a particular emphasis on algorithms that would be either very fast in software or very resource-efficient in hardware. Algorithm designers

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-67772204473135764402008-08-11T21:09:00.000+03:002010-08-14T04:56:24.443+03:00

In public key cryptography, the general idea is to design ciphers based difficult problems that take very long time to solve. These systems utilize a private and a public key, where the public key is used to encrypt messages and the private key is used for decryption. The security of these cryptosystems is based on the fact that the private key can be computed from the public key only by solving

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-18384825953963593502008-08-11T20:57:00.000+03:002008-10-23T21:47:16.744+03:00

Side channel attacks utilize implementation-specific characteristics such as time delays, power consumptions or electromagnetic radiation. Since these attacks are implementation specific, physical implementation of the cipher is very critical, even tiny changes may result in big differences in security.Timing attacks and power analysis are important types of side channel attacks. In timing

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-67623232003705742522008-06-10T15:11:00.000+03:002008-10-23T21:47:16.745+03:00

Hash function are fundamental components of many cryptographic applications such as digital signatures, random number generation, integrity protection, e-cash etc. Employing hash functions for these applications both increase the security and improve the efficiency of these systems. However, availability of any weaknesses in hash function designs is a very serious threat against the security of

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-39025904399008488132008-05-19T21:11:00.000+03:002010-08-14T04:56:24.443+03:00

I defended my PhD thesis on 24th of April. The title is "On Statistical Analysis of Synchronous Stream Ciphers". My presentation. Here is the abstract:Synchronous stream ciphers constitute an important class of symmetric ciphers. After the call of the eSTREAM project in 2004, 34 stream ciphers with different design approaches were proposed. In this thesis, we aim to provide a general framework

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-49001709571386130102008-05-19T17:01:00.000+03:002008-10-23T21:47:16.746+03:00

This study is a joint work with A. Doganaksoy and Ç. Çalık. We presented this study in SASC06 Stream Ciphers Revisited, Leuven Belgium, 2006,pdf Here is the abstract:Synchronous stream ciphers produce long keystreams to beXORed with plaintext. The output keystreams should be indistinguishablefrom truly random sequences and should not leak any informationabout the secret key and the internal state

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-4501182529067791782008-05-15T19:21:00.000+03:002010-08-14T04:56:24.444+03:00

Together with Prof. Thomas Johansson and Hakan Englund, I wrote a paper on d-monomial distinguishers and presented it at Indocrypt 2007, Chennai pdf Here is the abstract: Saarinen recently proposed a chosen IV statistical attack, called the $d$-monomial test, and used it to find weaknesses in several proposed stream ciphers. In this paper we generalize this idea and propose a framework for chosen

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In SASC 2007, we presented a linear approximation for reduced round Trivium. Here is the abstract of the paper:Existence of linear approximations based on key, IV and outputbits with non-negligible biases is a serious threat for thesecurity of synchronous stream ciphers. In this study, we focus onthe cipher Trivium, which is one of the strong candidates of theECRYPT project. No weaknesses of full

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It was supervised by Asst. Prof. Dr. Haldun Süral and Prof. Dr. Nur Evin Özdemirel. If you want to reach its full pdf, please send me an email. Here is the abstract:In traveling salesman problem (TSP), salesman visits N cities exactly ones and returns back to where he starts. When problem size increase, it gets harder to find the optimal solution in a reasonable time; many heuristics are

Meltem Sonmez Turanhttp://www.blogger.com/profile/01583849583555999403noreply@blogger.com0tag:blogger.com,1999:blog-7157713118001680685.post-68337556285980198302008-05-14T16:35:00.000+03:002008-05-17T12:23:54.026+03:00

My new blog is officially on. Please feel free to comment and share ideas.Best regards,Meltem

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