Kljuc
Shield from interference
35 – Cryptographic-key source
Noise
source
Amplifier
A/D
S&H
Natural sources of random signals:
Thermal noise
Shot noise
Avalanche breakdown
Radioactive decay
...
Clock
Sampling
Quantization
Address counter
Memory
Interference is not random!
Interference might be intentional!
Arbitrary-length cryptographic key:
Password (rather short key...)
Keys for DES, AES etc
One-time pad
(very long but unbreakable key!)