add block frequency test

CHANGELOG.md

@@ -9,5 +9,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 - Added a simple monobit test.
+- Added a block frequency test.
 
 [Unreleased]: https://git.chir.rs/ProcyOS/rand_testsuite

Cargo.lock

@@ -32,6 +32,15 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "extra-math"
+version = "0.1.0"
+source = "git+https://git.chir.rs/ProcyOS/extra_math.git#38d6abf85718d053f45c6b77c88607f245be55e0"
+dependencies = [
+ "libm",
+ "num-traits",
+]
+
 [[package]]
 name = "funty"
 version = "2.0.0"
@@ -139,6 +148,7 @@ name = "rand_testsuite"
 version = "0.1.0"
 dependencies = [
  "bitvec",
+ "extra-math",
  "libm",
  "num-traits",
  "rand",

Cargo.nix

@@ -22,7 +22,7 @@ args @ {
   workspaceSrc,
   ignoreLockHash,
 }: let
-  nixifiedLockHash = "0c97699175df8652eb6708b342caa7bcc3794d5a6bd83ecc4362d8cf3b262349";
+  nixifiedLockHash = "a2b590ebe54f290db87e552bf935f4bb11098b9ba02841e8ed499aad10c57419";
   workspaceSrc =
     if args.workspaceSrc == null
     then ./.
@@ -113,6 +113,25 @@ in
       };
     });
 
+    "git+https://git.chir.rs/ProcyOS/extra_math.git".extra-math."0.1.0" = overridableMkRustCrate (profileName: rec {
+      name = "extra-math";
+      version = "0.1.0";
+      registry = "git+https://git.chir.rs/ProcyOS/extra_math.git";
+      src = fetchCrateGit {
+        url = "https://git.chir.rs/ProcyOS/extra_math.git";
+        name = "extra-math";
+        version = "0.1.0";
+        rev = "38d6abf85718d053f45c6b77c88607f245be55e0";
+      };
+      features = builtins.concatLists [
+        ["default"]
+      ];
+      dependencies = {
+        libm = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".libm."0.2.8" {inherit profileName;}).out;
+        num_traits = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".num-traits."0.2.19" {inherit profileName;}).out;
+      };
+    });
+
     "registry+https://github.com/rust-lang/crates.io-index".funty."2.0.0" = overridableMkRustCrate (profileName: rec {
       name = "funty";
       version = "2.0.0";
@@ -332,6 +351,7 @@ in
       ];
       dependencies = {
         bitvec = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".bitvec."1.0.1" {inherit profileName;}).out;
+        extra_math = (rustPackages."git+https://git.chir.rs/ProcyOS/extra_math.git".extra-math."0.1.0" {inherit profileName;}).out;
         libm = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".libm."0.2.8" {inherit profileName;}).out;
         num_traits = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".num-traits."0.2.19" {inherit profileName;}).out;
         ${

Cargo.toml

@@ -11,6 +11,7 @@ categories = ["development-tools::testing", "no-std", "no-std::no-alloc"]
 
 [dependencies]
 bitvec = { version = "1.0.1", default-features = false }
+extra-math = { git = "https://git.chir.rs/ProcyOS/extra_math.git", version = "0.1.0" }
 libm = "0.2.8"
 num-traits = { version = "0.2.19", default-features = false, features = [
     "libm",

src/tests.rs

@@ -1,5 +1,6 @@
 //! All supported tests are available in this module.
 
+mod block_frequency;
 mod monobit;
 
 use bitvec::prelude::{BitOrder, BitSlice, BitStore};

src/tests/block_frequency.rs

@@ -0,0 +1,65 @@
+//! Block Frequency Test
+
+use bitvec::prelude::{BitOrder, BitSlice, BitStore};
+use extra_math::gamma::Gamma;
+#[allow(unused_imports, reason = "redundant in std use cases")]
+use num_traits::Float;
+
+use crate::RandomTest;
+
+/// The Block Frequency Test splits the input data into multiple blocks, counts the frequency 1s and 0s within these blocks, and determines whether these are distributed well.
+///
+/// The amount of blocks is chosen such that a block is at least 1% of the size of the total input, or at least 20.
+///
+/// This test is defined in the [NIST Special Publication 800-22](https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-22r1a.pdf).
+
+#[derive(Copy, Clone, Debug)]
+pub struct BlockFrequency;
+
+impl RandomTest for BlockFrequency {
+    const RECOMMENDED_BIT_SIZE: usize = 100;
+
+    const MINIMUM_BIT_SIZE: usize = 0;
+
+    fn evaluate<T: BitStore, O: BitOrder>(&self, bs: &BitSlice<T, O>) -> Option<f64> {
+        let block_size = (bs.len() / 100).max(20);
+        let block_count = bs.len() / block_size;
+        let mut statistic = 0.0;
+        for i in 0..block_count {
+            let one_count: usize = bs[i * block_size..(i + 1) * block_size]
+                .into_iter()
+                .map(|v| if *v { 1 } else { 0 })
+                .sum();
+            let pi = (one_count as f64) / (block_size as f64);
+            statistic += (pi - 0.5).powi(2);
+        }
+        statistic *= (4 * block_size) as f64;
+        Some(Gamma::upper_gamma_regularized(
+            block_size as f64 / 2.0,
+            statistic / 2.0,
+        ))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use bitvec::prelude::*;
+
+    use crate::RandomTest;
+
+    use super::BlockFrequency;
+
+    #[test]
+    fn block_frequency_test_vector() {
+        let epsilon = bitvec![
+            1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0,
+            0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0,
+            1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1,
+            0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0
+        ];
+        let res = BlockFrequency.evaluate(epsilon.as_bitslice());
+        assert!(res.is_some());
+        let res = res.unwrap();
+        assert!(res > 0.01, "Data should be evaluated as random");
+    }
+}