Class |
Topic |
1M 4/01 |
Basics. Read the syllabus.
Introduction: four basic problems in cryptography:
{priv, auth} x {sym, asym}.
Other ways to create asymmetry.
|
1W 4/03 |
Quiz.
Secret Key Exchange (SKE) and the DH protocol.
Mean salary computation in the physical and communication model.
|
1R 4/04 |
PS1 in discussion section |
1F 4/05 |
Defined groups. Z_2, Z_N, Z_2^*.
Why Z_2^* is cryptographically useful.
The OTP encryption scheme.
|
2M 4/08 |
Quiz. Reviewing OTP encryption. Correctness.
Defining perfect privacy for one message or multiple messages. |
2W 4/10 |
Review. Secret sharing:
2-of-2, threshold schemes, definition for the general problem. |
2R 4/11 |
Solutions to PS2. Map a deal to a point in Z_{C(52,26)}. Breaking LR-privacy for
a deterministic, stateless enc scheme.
|
2F 4/12 |
Quiz. Privacy notion for secret sharing (SS). Shamir SS
(original paper)
Pseudorandom generators (PRGs). RC4 |
3M 4/15 |
Approaches to handling the domain & stretch of a PRG. Reductions.
From stretch-1 to long-stretch. |
3W 4/17 |
∃ secure asym PRG ⇒ P≠NP.
A reduction: if g is a secure stretch-1 PRG then
G[g] is a secure arbitrary-stretch PRG.
Problems with RC4/PRGs.
|
3R 4/18 |
Solutions to PS3. Defining indistinguishability.
Asymptotic way to do that. |
3F 4/19 |
Quiz. Problems with PRGs and with RC4.
Syntax of a PRF (pseudorandom function).
A well-designed PRF: Dan Bernstein’s
ChaCha20
|
4M 4/22 |
The PRF security notion. |Func(n,m)|.
Using a PRF to encrypt: prob. enc. with a PRF / ChaCha20.
|
4W 4/24 |
Quiz. Notions of enc scheme security: LR, ind0, ind$. LR-security is
equivalent to ind0-security. ind$ security is stronger. |
4R 4/25 |
An alternative Chernoff bound for the HW.
A more efficient way to use a minimal-stretch PRG. |
4F 4/26 |
Finishing the reduction for ind$ ⇒ ind0.
Syntax for blockcipher. Signatures and initial history of DES and AES. |
5M 4/29 |
Syntax and security definition for blockciphers.
How DES works. Why it’s key is so short. |
5W 5/01 |
Cat Day: visits from Peanut and Cloud.
Winner’s Do Artifacts have Politics? (recommended),
and the key length of DES. AES. Arithmetic in GF(2^8).
|
5R 5/02 |
Going over a practice quiz, including substitution ciphers and
password guessing. Review of GF(2^8) multiplication.
|
5F 5/03 |
Quiz. Using a PRP to encrypt: ECB mode mode and critique. CTR mode.
The PRP/PRF switching lemma.
|
6M 5/06 |
Game-playing arguments; finish PRP/PRF switching lemma.
Proving security of CTR mode. CBC encryption.
Malleability of CBC-encrypted text. |
6W 5/08 |
CBC-ctr is not ind-secure;
CBC$ is. Nonmalleability.
CTR and CBC are malleable.
MT cutoff. Then:
the CBC MAC. The definition of a MAC. |
6R 5/09 |
Midterm review sessions: we worked out old midterms, as well as the
last problem on the current problem sets. |
6F 5/10 |
Midterm 1. Cheat-sheet allowed (one side of one page).
Overflow room: Wellman 207. About 20 students should go
there.
|
7M 5/13 |
Midterms weren't great. A dog visits. MACs.
PRFs are good MACs. Raw CBC MAC: no good. Fixing it: CMAC.
Carter-Wegman MACs. GMAC.
|
7W 5/15 |
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7R k/16 |
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7F 5/17 |
. |
8M 5/20 |
Deadline for +4% early-turnin final-project. |
8W 5/22 |
. |
8R 5/23 |
. |
8F 5/24 |
. |
9M 5/27 |
Deadline for +3% early-turnin final project.
Holiday; no school; you’ll be lonely in Wellman.
|
9W 5/29 |
. |
9R 5/30 |
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9F 5/31 |
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10M 6/03 |
Midterm 2. Final projects due at 10 pm.
Overflow room is Wellman 115 (about 28 students should go
there). |
10W 6/05 |
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