update typo and structures

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Trance-0
2024-12-16 13:41:24 -06:00
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commit d471db49c4
24 changed files with 328 additions and 219 deletions

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@@ -1,6 +1,6 @@
# Lecture 16
## Continue on PRG
## Chapter 3: Indistinguishability and Pseudorandomness
PRG exists $\implies$ Pseudorandom function family exists.
@@ -49,13 +49,13 @@ Pseudo random function familiy exists $\implies$
Mult-message secure encryption exists.
## Public key cryptography
### Public key cryptography
1970s.
The goal was to agree/share a key without meeting in advance
### Diffie-Helmann Key exchange
#### Diffie-Helmann Key exchange
A and B create a secret key together without meeting.
@@ -75,7 +75,7 @@ And Alice do $(g^b)^a$ where Bob do $(g^a)^b$.
With $g^a,g^b$ no one can compute $g^{ab}$.
### Public key encryption scheme
#### Public key encryption scheme
Ideas: The recipient Bob distributes opened Bob-locks
@@ -90,12 +90,12 @@ Public-key encryption scheme:
Let $A, E$ knows $pk$ not $sk$ and $B$ knows $pk,sk$.
Adversary can now encypt any message $m$ with the public key.
Adversary can now encrypt any message $m$ with the public key.
- Perfect secrecy impossible
- Randomness necessary
- Randomness necessary
Security of public key
#### Security of public key
$\forall n.u.p.p.t D,\exists \epsilon(n)$ such that $\forall n,m_0,m_1\in \{0,1\}^n$
@@ -113,7 +113,9 @@ We will achieve security in sending a single bit $0,1$
Time for trapdoor permutation. (EX. RSA)
Encryption Scheme: Given family of trapdoor permutation $\{f_i\}$ with hardcore bit $h(i)$
#### Encryption Scheme via Trapdoor Permutation
Given family of trapdoor permutation $\{f_i\}$ with hardcore bit $h(i)$
$Gen(1^n):(f_i,f_i^{-1})$, where $f_i^{-1}$ uses trapdoor permutation of $t$