Quick Screen & Health Diagnostic Suite
Instant single-pass randomness screening and health diagnostics across 5 critical dimensions: Information, Frequency, Bit Distribution, Sequential Patterns, and Geometry.
100% Zero-Allocation WebAssembly: Stream multi-megabyte entropy sources and cryptographic files in real time directly inside your browser. No data ever leaves your device.
5-Dimensional Randomness Diagnostics
The Quick Screen battery provides a rapid, high-confidence health assessment of hardware TRNGs, PRNGs, and cryptographic keys across 10 vital statistical metrics:
| ID | Test Metric | Dimension | Pass Criteria (α=0.05) | Diagnostic Purpose |
|---|---|---|---|---|
| QK01 | Shannon Entropy ($H$) | Information Density | $\ge 7.90$ bits/byte | Quantifies information density per 8-bit symbol. |
| QK02 | Min-Entropy ($H_\infty$) | Information Density | $\ge 7.00$ bits/byte | Worst-case unpredictability based on the most frequent byte ($-\log_2 p_{\max}$). |
| QK03 | Optimum Compression | Information Density | $\le 1.0\%$ reduction | Theoretical lossless compression limit via Huffman coding. |
| QK04 | Byte Uniformity ($\chi^2$) | Spectral Uniformity | $218.42 \le \chi^2 \le 293.25$ | Goodness-of-fit across all 256 byte values ($df=255$). |
| QK05 | Arithmetic Mean | Spectral Uniformity | $127.5 \pm 1.0$ | Verifies balance across the byte spectrum $[0, 255]$. |
| QK06 | Monobit Frequency | Bit Distribution | $p\text{-value} \ge 0.01$ | Ratio of zeros to ones across raw bitstream ($50.0\%$). |
| QK07 | Runs Structure | Bit Transitions | $p\text{-value} \ge 0.01$ | Frequency of uninterrupted identical bit sequences. |
| QK08 | Poker Test (4-bit) | Sequential Patterns | $\chi^2 \le 30.58$ ($df=15$) | Uniformity of 16 possible 4-bit nibbles. |
| QK09 | Serial Correlation | Dependence | $\|r\| \le 0.01$ | Evaluates byte-to-byte lag-1 linear autocorrelation. |
| QK10 | Monte Carlo $\pi$ | Geometric Convergence | Error $\le 1.0\%$ | Spatial independence via random point distribution inside unit square. |
Visual $\chi^2$ Density Curve
The interactive plot displays the exact Chi-Square probability density function ($df=255$) overlaid with critical rejection thresholds ($\alpha = 0.01, 0.05, 0.10$). Your sample’s measured $\chi^2$ value is pinpointed with a live indicator.
When to Use Quick Screening
- Hardware TRNG Continuous Health Monitoring: Rapid startup tests for noisy diode or ring-oscillator physical entropy sources before seeding cryptographic DRBGs.
- Cryptographic Key & IV Validation: Sanity-checking generated AES-256 keys, RSA primes, nonces, and initialization vectors against weak entropy failure.
- PRNG Pipeline Triage: Pre-screening software generators (e.g. Xoshiro256**, ChaCha20, LCG) prior to running compute-heavy full batteries like Dieharder or TestU01.
- Firmware & Telemetry Diagnostics: Verifying sensor noise streams or embedded IoT entropy harvesters under extreme operating temperatures.
Engineering Tip: If a stream fails QK04 ($\chi^2$) with an extremely low score ($\chi^2 < 180$), it indicates artificial over-uniformity (such as a counter or shuffle). If it fails with a high score ($\chi^2 > 320$), it indicates severe bias or clustering.