Tel Aviv University

School of Computer Science

Foundations of Cryptography

0368.4162

Fall Semester 2017/2018

# News

### Clarification about HW4 Q1.b

The question wasn't formulated properly in two ways.

1. You're not meant to show that there exists secret-key KPA schemes out of thin air (as you know by now, their existence is equivalent to that of OWFs). Your meant to show that if there are such KPA schemes then there are such that are not CPA secure. Thanks to Yotam for pointing out.

2. You're not meant to do this for bit-encryption schemes (like in item c). Thanks to Nathan for pointing out. In fact, as Nathan pointed out in the forum it is untrue for bit encryption schemes.

(21 Dec 2017 19:34)

### Assignment 4

Assignment 4 is now posted and is due Dec 28.

(14 Dec 2017 20:49)

### HW1: Reference Solutions

Dear all,

Here you can find three reference solutions for HW1.

The first two are by Nathan and Omri.

The third is my solution for questions 1,3, and is supposed to give you some impression of what I consider "concise but yet convincing".

Note: in the Bonus solutions of Omri and Nathan there's a slight inaccuracy (although they definitely got the main point), try to figure out what the issue is.

(01 Dec 2017 21:32)

### Assignment 3 is posted and is due 14 Dec.

Assignment 3 is posted and is due 14 Dec.

Make sure to note your collaborators and any external sources. If you don't use any, explicitly write "none".

(30 Nov 2017 21:28)

### Running time of A' in question 3

Question 3.b wasn't accurate, running time of $A'$ should also include a factor of $time(f)$ —- the time to compute $f$. No points will be taken off for correspondingly inaccurate time analysis.

(30 Nov 2017 20:44)

### Assignment 2 is posted and is due 30 Nov.

Assignment 2 can be found here.

(15 Nov 2017 11:48)

### Class has moved to Dan David 202

We will have a whiteboard.

(06 Nov 2017 13:19)

### Signup for Scribing Lecture Notes

Read the instructions and sign up for scribing lecture notes here.

(21 Oct 2017 12:40)