← Entropy Atlas
Secret & unpredictable
Private signing & key-agreement keys
Public-key systems begin with a private value that must be selected correctly and kept secret.
Evaluation card
What “plenty” means here.
- Required property
- Generation that follows the scheme’s exact distribution and range rules, using a cryptographic random generator.
- If it fails
- Bias, invalid sampling, or a repeated seed can reveal the private key even when the public-key mathematics is sound.
- Relevant attacker
- Observers of public keys, signatures, handshakes, or compromised generator state.
- The Plenty Line
- Meet the scheme’s documented generation procedure and target security strength; use rejection sampling where required.
- Why more is not automatically better
- Extra random bytes do not help if they are reduced incorrectly or the scheme’s security level is lower.
Where it appears
Recognize the pattern.
- 01Ed25519 signing keys
- 02elliptic-curve key agreement
- 03RSA prime generation
The Plentropy rule
Protect the requirement, then stop.
Meet the scheme’s documented generation procedure and target security strength; use rejection sampling where required.
Once that claim has comfortable evidence and margin, improve the next limiting factor instead of worshipping a larger entropy number.