Entropy source
An entropy source is a physical, computational, or operating-system process that supplies unpredictable or uncertain input for generating random data.
Hacking Cryptography
A physical or computational process that supplies uncertain values from which random output can be derived.
- How it is used
- Supplies uncertain values for TRNG output before extraction and application use.
- How deep it goes
- Explains physical modeling, raw-output inspection, extraction, health checks, and attacks, but does not derive circuit designs.
- Examples
- Uses Zener noise, ring oscillators, Intel RDRAND, USB TRNGs, and ambient-temperature bias as examples.
- What you can do after
- Evaluate TRNG designs by checking physical justification, raw-output visibility, health shutdown, extraction, and resistance to physical or host attacks.
Real-World Cryptography
An entropy source is a physical or computational process that supplies unpredictable or partially unpredictable input for random-data generation.
- How it is used
- Supplies unpredictable input that operating systems use to generate security-sensitive random values.
- How deep it goes
- Explains source types, entropy quality, startup predictability, physical randomness, and PRNG seeding without detailing extraction algorithms.
- Examples
- Uses mouse movement, interrupts, disk-seek timing, thermal noise, and Cloudflare’s LavaRand wall as examples.
- What you can do after
- Evaluate randomness pipelines by identifying entropy sources, recognizing weak startup conditions, and understanding why systems seed PRNGs.
Related concepts
- crypto/rand packageused by · The crypto/rand package is Go’s standard-library package for generating cryptographically secure random data from system-provided entropy sources.
- cryptographically secure random number generatorused by · A cryptographically secure random number generator produces computationally unpredictable values while resisting prediction and recovery of its internal state by feasible adversaries.
- pseudo-random number generatoruses · A pseudorandom number generator is a deterministic computational process that uses an initial seed or internal state to produce a sequence with random-like statistical properties.
- operating systemused by · An operating system is system software that manages computer hardware and provides services and interfaces for application programs.
- true random number generatorused by · A true random number generator produces unpredictable values by sampling nondeterministic physical phenomena rather than relying solely on deterministic algorithms.
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