This video is one of my latest works in amateur astrophotography. It's a time lapse video made out of more than 4 hours of photo shooting. The location is Semnan, Iran. I hope you enjoy it.

Poster of Lattice-based Cryptography Workshop

One of my hobbies is designing computer graphics, specifically posters. The image above is my latest design for "Lattice-based Cryptography Workshop" which would be held on May in Sharif University. Usually I do this kind of works for my supervisors. However this time I did it for Dr. Eghlidos, one faculty member of our department. She allowed me to let my creativity free therefore the result was satisfying for me. Because my other posters before was not what I wanted. I hope this poster would be interesting to you.

Scott Alexander Vanstone passed away

Condolences to international cryptography community
http://www.iacr.org/people/Vanstone.html

He was a co-authors of, the well-known book, "Applied Cryptography".

Acoustic cryptanalysis

Check this out.

Maybe the most interesting part of this paper is the attack using just a mobile phone in 30 centimeter distance of victim laptop. This side channel attacks are one the most near to spying stuff things in cryptography. In the fifteenth question of the page, two documented real world acoustic attacks carried out by MI5 and some-not-mentioned-organisation in USA has been exampled.

There is also a wiki page for this attack.

Users assumption about what security a system provides

On Bruce Schneier blog there was a post about arresting of a student who has sent email bomb threat to Harvard for skipping a final exam. Although he has used Tor network for anonymization, FBI has identified and arrested him by going through a list of Harvard users who has accessed Tor.

In cryptography, we believe that usually the weakest parts of the whole security system are users. Additionally, I believe that the problem mostly arises when users have some false assumptions about what sort of security the system provides. In this case, the user, the cheating student, supposed that Tor can anonymize him among the whole users of the internet or at list whole users of Harvard, contrary to his expectations Tor network just anonymize the user among users of its own network and in this case the users of its own network that are behind the University's gateway. The rest is just some police mechanisms.

In my opinion, there should be enough clarifications for users about what type and level of security the system provides. This clarification is a hard process as the users are not experts. Besides, this clarification is mostly a duty of system designers.