02/26/2008 (Tu, Lecture 8): We discussed a signature scheme based on RSA and then
described authenticated Diffie-Hellman key exchange protocol which addresses the MITM
attack described earlier. We also discussed the concept of blind signatures based on RSA. We started discussing hash functions and described some requirements of hash functions, such as one-way and weak collision resistance.
02/28/2006 (Th, Lecture 9): We discussed the random-oracle model of hash functions and
then used it to prove the "ciphertext indistinguishability" property of a public-key crypto-system based on RSA. We also discussed hash-chains and Merkle hash trees. We discussed the basic architecture of an iterated hash function. We covered a specific
hash function called MD5.
Monday, March 3, 2008
Week 4
02/12/2008 (Tu, Lecture 6): We finished our discussion on mathematical background
needed for public-key cryptography. We started discussing the public-key crypto-system
called RSA. The proof that RSA works uses the Chinese Remainder Theorem (CRT).
02/14/2008 (Th, Lecture 7): We discussed the public-key crypto-system by Elgamal.
The security of this crypto-system depends on the hardness of the discrete-log problem.
We also covered the Diffie-Hellman key exchange protocol and discussed a man-in-the-middle
(MITM) attack on this protocol. We also briefly discussed the concept of zero-knowledge
proofs (ZKP).
needed for public-key cryptography. We started discussing the public-key crypto-system
called RSA. The proof that RSA works uses the Chinese Remainder Theorem (CRT).
02/14/2008 (Th, Lecture 7): We discussed the public-key crypto-system by Elgamal.
The security of this crypto-system depends on the hardness of the discrete-log problem.
We also covered the Diffie-Hellman key exchange protocol and discussed a man-in-the-middle
(MITM) attack on this protocol. We also briefly discussed the concept of zero-knowledge
proofs (ZKP).
Week 3
02/05/08 (Tu, Lecture 4): In this lecture we covered simple DES and then "full"
DES by analogy. We also discussed various modes of operation (such as ECB, CBC, OFB, and CTR). These modes of operation allow you to use block ciphers to process arbitrary sized messages.
02/07/08 (Th, Lecture 5): We finished our discussion on modes of operation. We
covered 2DES and 3DES. Moreover, we showed a meet-in-the-middle attack on
2DES. We started discussing mathematical background that we need for covering public-key cryptography. Some of the topics are GCD, Fermat's Little Theorem (FLT), and Chinese Remainder Theorem (CRT). I handed out a 5-page document on these topics.
DES by analogy. We also discussed various modes of operation (such as ECB, CBC, OFB, and CTR). These modes of operation allow you to use block ciphers to process arbitrary sized messages.
02/07/08 (Th, Lecture 5): We finished our discussion on modes of operation. We
covered 2DES and 3DES. Moreover, we showed a meet-in-the-middle attack on
2DES. We started discussing mathematical background that we need for covering public-key cryptography. Some of the topics are GCD, Fermat's Little Theorem (FLT), and Chinese Remainder Theorem (CRT). I handed out a 5-page document on these topics.
Tuesday, February 5, 2008
Week 2
Lecture 2 (01/29/08, Tu): We covered some general terms related to security, such as
various attack models (chosen plaintext/ciphertext). We discussed various classical
ciphers. We covered one-time-pad and how they can be made practical using psuedo-random
number generators (PRGs). We spend some time on the Blum-Blum-Shub (BBS) PRG. More
information about the BBS generator can be found in the handbook (which is linked to
the class web-page).
Lecture 3 (01/31/08, Th): We covered linear feedback shift registers (LFSRs) and showed
a known plaintext attack on it (the attack was based on the linear relationship between
the bits of the keystream). We discussed one way to break the non-linearity (called the
Geffe generator). We discussed Fiestel cipher, which is a general way to build block ciphers.
various attack models (chosen plaintext/ciphertext). We discussed various classical
ciphers. We covered one-time-pad and how they can be made practical using psuedo-random
number generators (PRGs). We spend some time on the Blum-Blum-Shub (BBS) PRG. More
information about the BBS generator can be found in the handbook (which is linked to
the class web-page).
Lecture 3 (01/31/08, Th): We covered linear feedback shift registers (LFSRs) and showed
a known plaintext attack on it (the attack was based on the linear relationship between
the bits of the keystream). We discussed one way to break the non-linearity (called the
Geffe generator). We discussed Fiestel cipher, which is a general way to build block ciphers.
Sunday, January 27, 2008
Week 1
Tu (01/22/08): We discussed the organization of the class. For example, we discussed various security primitives (encryption, hashing, signatures) and functionality provided by them. Then
we discussed how these primitives can be composed to construct services (such as SSL and
Kerberos). We also discussed logistics and schedule of the class.
Th (01/24/08): Instructor was out of town.
we discussed how these primitives can be composed to construct services (such as SSL and
Kerberos). We also discussed logistics and schedule of the class.
Th (01/24/08): Instructor was out of town.
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