Checksum Verifier 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-clean

Evidence ID

t4-076

Effect

Computation or source lookup only

Input and validation requirements

The specification does not define text encoding or whether hexadecimal checksum comparison is case-sensitive. The convention probe therefore produces match=true under the stated UTF-8, case-insensitive convention but strict case-sensitive comparison would produce mismatch=false for the same visible input and expected checksum.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

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

{
  "inputs": {
    "algorithm": "CRC32",
    "text": "123456789",
    "expected_checksum": "cbf43926",
    "encoding": "UTF-8"
  },
  "expected_outputs": {
    "computed_checksum": "cbf43926",
    "match": true
  },
  "working": "UTF-8 bytes: 31 32 33 34 35 36 37 38 39. Initialize CRC register = FFFFFFFF. Apply the reflected CRC-32 recurrence for all 9 bytes using polynomial EDB88320. Register after the final byte = 340BC6D9. Apply final XOR: 340BC6D9 XOR FFFFFFFF = CBF43926. Format as 8 lowercase hexadecimal characters: cbf43926. Compare cbf43926 with cbf43926: equal, so match = true."
}

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