mirror of
https://github.com/jackyzha0/quartz.git
synced 2025-12-25 13:54:05 -06:00
40 lines
1.0 KiB
Markdown
40 lines
1.0 KiB
Markdown
---
|
|
title: "randomness"
|
|
aliases:
|
|
tags:
|
|
- comp210
|
|
---
|
|
|
|
- a lack of predicability
|
|
- no patterns
|
|
- stochastic (can be analysed but not predcted) vs deterministic
|
|
|
|
used for
|
|
- one time pad
|
|
- generating key-pairs
|
|
- generating salts for password hashing
|
|
- seeding pesudo random number generators
|
|
|
|
humans are not good at randomness
|
|
- e.g., see patterns when there are none
|
|
- e.g., random dot pattern
|
|
- shuffle algorithm
|
|
- gambers fallacy
|
|
|
|
how to prove randomness
|
|
- cannot prove
|
|
- but can check for uniformity, bias, distribution etc.
|
|
- difficult with small samples
|
|
- can identify data that is unlikely to be random
|
|
- (rngtext, diehard, dieharder etc)
|
|
|
|
# In computers
|
|
computers have the same problem: they are deterministic
|
|
- cannot really produce true random numbers
|
|
- CSPRNGS crypto secure pseudo random number generators
|
|
- hardware entropy generator
|
|
|
|
entropy pool
|
|
- modern OSs implement an entropy pool that processes can draw on when the need random data
|
|
- some systems provide blocking and non-blocking random source devices
|
|
- blocking: will stop when entropy is exhausted |