Cargo Features
deep_causality_rand has no features set by default.
[dependencies]
deep_causality_rand = { version = "0.1.13", features = ["aead-random", "os-random"] }- aead-random = chacha20poly1305, getrandom, zeroize
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Enables a secure, fast, non-NIST software CSPRNG based on the chacha20poly1305 algorith. The chacha20poly1305 was audited by NCC Group with no significant findings. Strongly prefer this CSPRNG implementation over os-random due to multiple known and potentially still unknown backdors in NIST cryptography standards and even hardware implementations of NIST Standards.
Authenticated Encryption with Associated Data (AEAD) Algorithms https://docs.rs/aead/latest/aead/index.html ChaCha20Poly1305 https://github.com/RustCrypto/AEADs/tree/master/chacha20poly1305
Hybrid Entropy Hardware Source: 32 bytes from getrandom (OS CSPRNG Software Source: A 64-bit entropy pool derived from:
- SystemTime (absolute epoch time, nanosecond precision)
- Instant (monotonic uptime, nanosecond precision)
- ThreadId (hashed using RandomState)
- Stack Address (ASLR memory layout)
Mixing Function:
- The hardware seed is split into four 64-bit chunks.
- The software entropy is XORed into each chunk, rotated by a prime multiple for each chunk to avoid pattern repetition.
Security Guarantees
Hardware Trust: If the hardware RNG is honest, the seed is 256-bit secure. This is the current gold standard for top-secret communication Backdoor Resistance: If the hardware RNG is backdoored (predictable), the seed is XORed with high-resolution timing and memory layout data (Unknown ^ Known = Unknown), breaking the adversary's ability to predict the CSPRNG state because an estiamted ~65 - 70 bits residulate entropy remain.
Source of non-hardware entropy:
- System Time (Nanosecond precision): ~10 bits
- ASLR (Stack + Heap Address): ~40 bits
- RDTSC (CPU Cycle Counter): ~20 bits
Total Estimate: ~70 - 80 bits
Even in case of a fully compromised Hardware RNG, a ~70 - 80 bits seed remains computationally infeasible to crack for a very long time as this would require multiple super computers for a single seed.
Motivation: NSA backdor in NIST AES hardware acceleration: https://www.youtube.com/watch?v=LvCXBO0Vx7Q NSA backdor in NIST AES key generation: https://www.youtube.com/watch?v=mdsoWCry23Y NSA backdor in NIST Dual_ec_drbg: https://www.youtube.com/watch?v=xanhbvtc5bY NSA backdor in NIST DES cypher: https://www.youtube.com/watch?v=jwKCLmzRE6o
Affects
chacha_rng::ChaCha20Rng,rand::chacha_rng… - os-random = getrandom
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Enables random number generator from the host OS.
Enabling os-random adds an indirect depdency on getrandom and libc.
Disabled by default. Use aead-random instead to protect against hardware RNG attacks.Affects
rand::os_random_rng,os_random_rng::OsRandomRng…
Features from optional dependencies
In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.