rand_jitter
Non-physical true random number generator based on timing jitter.
This crate depends on rand_core and is part of the Rand project.
This crate aims to support all of Rust's std
platforms with a system-provided
entropy source. Unlike other Rand crates, this crate does not support no_std
(handling this gracefully is a current discussion topic).
Links:
Features
This crate has optional std
support which is disabled by default;
this feature is required to provide the JitterRng::new
function;
without std
support a timer must be supplied via JitterRng::new_with_timer
.
Quality testing
JitterRng::new()
has build-in, but limited, quality testing, however
before using JitterRng
on untested hardware, or after changes that could
effect how the code is optimized (such as a new LLVM version), it is
recommend to run the much more stringent
NIST SP 800-90B Entropy Estimation Suite.
Use the following code using timer_stats
to collect the data:
use JitterRng;
use Error;
use File;
use Write;
This will produce two files: jitter_rng_var.bin
and jitter_rng_min.bin
.
Run the Entropy Estimation Suite in three configurations, as outlined below.
Every run has two steps. One step to produce an estimation, another to
validate the estimation.
- Estimate the expected amount of entropy that is at least available with
each round of the entropy collector. This number should be greater than
the amount estimated with
64 / test_timer()
. - Estimate the expected amount of entropy that is available in the last 4
bits of the timer delta after running noice sources. Note that a value of
3.70
is the minimum estimated entropy for true randomness. - Estimate the expected amount of entropy that is available to the entropy
collector if both noise sources only run their minimal number of times.
This measures the absolute worst-case, and gives a lower bound for the
available entropy.
License
rand_jitter
is distributed under the terms of both the MIT license and the
Apache License (Version 2.0).
See LICENSE-APACHE and LICENSE-MIT, and COPYRIGHT for details.