Crypto News (2010A)

Exercise 4 is back

Tue, 02 Mar 2010 16:48:30 +0000

Feedback is always appreciated, right? so take back your HW#4 (and HW#3, if you hadn't already taken it).

Don't worry, we will maintain the conservative approximation of 100 to HW#4 grade when calculating the total HW grade (even though you may have a bit less…)

Moed A

Tue, 02 Feb 2010 12:40:18 +0000

Here is Moed A.

I also sent an email with sketch of solutions, but you'd better try to solve the exam on your own first.

First page of the exam

Wed, 20 Jan 2010 18:12:13 +0000

Mistake in Q3, HW #4

Sun, 17 Jan 2010 21:13:02 +0000

You'd better prove that $Pr\left(X_i^j \textrm{ is new}\right) > e^{-ijt/|X|$ ; this will make the next step more plausible.
Thanks to Yossi for pointing this out.

Sample exams

Fri, 15 Jan 2010 17:06:28 +0000

We don't have a whole lot of examples, but here are exams from the past years.

A clarification about Assignment 3

Sun, 27 Dec 2009 10:24:22 +0000

It might not be clear from Problem 1 itself, but Prudence is not required to recover $$p$$ in a single shot;
if, for example, in a single attempt she can rule out 10% of the remaining passwords in the dictionary, then with $\log_{10/9}(2^{30}) \approx 200$ attempts she can single out the correct password.

Due date of assignment #3

Sun, 20 Dec 2009 10:07:30 +0000

We decided you could use another week, so you may submit assignment 3 until December 30th.

Assignment 2, problem 3

Sat, 28 Nov 2009 16:43:21 +0000

Please note that when you are asked to find collisions wrt a hash function H, namely
two mssgs m1,m2 s.t. H(m1)=H(m2), these messages can be of different lengths.

Change of Deadline, Assignment 1

Sun, 08 Nov 2009 21:30:39 +0000

All problems except problem 3 (the substitution cipher questions) are due on Wed., Nov. 11, 6:20 pm, Israel time.

Problem 3 is due on Sunday, Nov. 15, 5 pm, Israel time.

In both cases, the destination is Rani Hod’s mailbox (second floor, Schreiber building).

FAQ

Sat, 07 Nov 2009 20:47:54 +0000

Hints and answers to FAQs appear now on the FAQ page.