# Introduction to Cryptography (89-656)

## (2010)

## General Information

**Semester A**

**Lecturer:**Prof. Yehuda Lindell

**Day and Time:**Sunday, 13:00-16:00 (lecture), 16:00-17:00 (recitation)

**Building:**604

**Room:**13

**Course site:**http://www.cs.biu.ac.il/~lindell/89-656/main-89-656.html

## Lecture Notes

Recitation 1

**(18.10)**: Historical Ciphers

Recitation 2

**(25.10)**: Perfect-Secret Encryption

Recitation 3

**(01.11)**: Psedurandom Generators

Recitation 4

**(08.11)**: Psedurandom Functions, Private-Key Encryptions

Recitation 5

**(15.11)**: Private key Encryptions (cont.), MACs, (notes)

Recitation 6

**(22.11)**: Collision-Resistant Hash Functions, DES

**UPDATED (27.01.10)**

Recitation 7

**(29.11)**: DES, 2-DES

Recitation 8

**(06.12)**: Number theory, RSA hardness assumption

Recitation 9

**(20.12)**: DL, CDH, DDH, Diffie-Helman Key Exchange protocol

**Note for the correction in the document (20.12) - How to calculate square root**

Recitation 10

**(03.01)**: Public Key, Textbook RSA, El-Gamal

Recitation 10b

**(03.01)**: Reductions

Recitation 11

**(10.01)**: El-Gamal, RSA

Recitation 12

**(17.01)**: Signatures, Random Oracle

Recitation 13

**(24.01)**: Secret Sharing, Questions from tests

All the recitations in a signle file

## Exercises

There will be 5 exercises during the semester (and not 6 as was planned). **All the students must submit all the exercises**; However, in calculating the final grade, only the best 4 exercises will be taken into consideration.

Note that the exercises are 25% of the final grade.

Exercise 2 (Due date: November 22.)

Exercise 3 (Due date: December 6. Late submission: December 14 - mailbox 58, or scanned by mail.)

Exercise 4 (Due date: January 3.)

Exercise 5 (Due date: January 24) Partial Solution

## Grades

## Announcements

Please note that exercise 5 is probably the most important exercise in the course. Therefore, I hope that students who already have good results so far will take this exercise seriously in order to get a good grade in the exam.