Password / Passphrase Entropy Estimator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-with-binding-errata

Evidence ID

t4-088

Effect

Computation or source lookup only

Input and validation requirements

Invalid zero guess rates can trigger undefined division, and the specification leaves exhaustive-versus-average crack time and rate-unit conventions insufficiently explicit. Zero-length input also requires explicit weak/invalid handling.

Required corrections

[
  {
    "vector": 2,
    "field": "exhaustive_crack_time_seconds",
    "wrong": 475920.314814,
    "correct": 475920314800000,
    "cause": "94^12/1e9 dropped a factor of 1e9 (v1/v3 crack times correct)"
  }
]

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "mode": "charset",
    "charset_size": 26,
    "length": 8,
    "guesses_per_sec": 1000000000
  },
  "expected_outputs": {
    "entropy_bits": 37.6035177451,
    "exhaustive_crack_time_seconds": 208.827064576
  },
  "working": "H = L·log2(N) = 8·log2(26) = 8·4.70043971814 = 37.6035177451 bits. Search space = 2^H = 26^8 = 208,827,064,576 guesses. Time = 208,827,064,576 / 1,000,000,000 = 208.827064576 seconds."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json
• tranche errata record