INKSEAL · QUALIFIED · V1.0 ZERTES · EIDAS IS SHA-256 ✓ TSA QUALIFIED ✓
Open Proof Standard · v1.0

Documentation is not proof.

InkSeal defines the standard for qualified digital proof — how documents, records, and evidence must be sealed to hold legal weight under Swiss and European law.

The Standard

What InkSeal defines

InkSeal is a specification for digital proof. It defines how any file — a photo, a report, an export from any tool — must be processed, timestamped, and packaged so that its existence at a specific point in time is independently verifiable and legally admissible.

The standard is tool-agnostic, industry-agnostic, and jurisdiction-aware.

original_hashSHA-256 over original file
timestamp_tokenRFC 3161 response from qualified TSA
tsa_authorityZertES or eIDAS qualified provider
geolocationGPS coordinates at time of capture (optional)
device_infoUser-Agent, platform identifier
proof_versionInkSeal Standard v1.0
verification_urlinkseal.org/verify

Timestamp

Qualified RFC 3161 timestamp from an accredited authority. Not a local clock. Not a blockchain. A state-supervised, legally recognized time source.

Integrity

SHA-256 hash ensures any modification — even a single byte — invalidates the proof. The original file is mathematically bound to the timestamp.

Independence

Verification requires no platform, no account, no vendor. The proof package contains everything needed to verify — with standard open-source tools.

Legal Framework

Jurisdiction-aware by design

InkSeal does not invent legal authority. It connects to the legal frameworks that already exist — and ensures proof packages meet their requirements.

Switzerland

Qualified timestamps from providers accredited by the Swiss Accreditation Service (SAS). Legally privileged evidence status.

ZertES · SR 943.03

European Union

Qualified timestamps from QTSPs on the EU Trusted List. Presumption of accuracy in all 27 member states.

eIDAS · Regulation (EU) 910/2014 · Art. 41

Client-side processing

Files never leave the user's device. Only the hash is transmitted. No data processing, no GDPR/DSG obligations for the implementer.

GDPR Art. 4(2) · nDSG Art. 5

Verification

Any party — courts, insurers, auditors — can verify an InkSeal proof independently using open-source tools and the TSA's public key.

RFC 3161 · ETSI EN 319 422
For Developers

Three lines of code

Add qualified digital proof to your existing application. Your users' files never touch our infrastructure. We handle the TSA routing — you get the proof package.

// npm install @inkseal/sdk

import { InkSeal } from '@inkseal/sdk'

const proof = await InkSeal.seal(file, {
  region: 'ch',    // → ZertES TSA
  partner: 'your-key'
})

proof.download()      // → .proof package
proof.verify()      // → verification URL

Sandbox

Free. Unlimited test seals with non-qualified timestamps. Full API access.

Production

From CHF 0.10/seal or monthly flat rate. Qualified ZertES/eIDAS timestamps. Revenue-split option available.

For Organizations

Certification mark

Organizations with their own timestamping infrastructure can certify their processes as InkSeal-conformant. The certification mark signals to courts, insurers, and auditors that the proof meets the standard.

Self-Service
Individuals & small business. Use the tool, get the seal.
API Partner
Embed InkSeal in your product via SDK.
Certified
Use the mark on your own proof documents.
Enterprise
Framework license for members, clients, or policyholders.
Intellectual Property

License

InkSeal Standard Specification

The InkSeal Standard Specification is published for reference and implementation. The following terms apply:

Certification Mark License

The InkSeal certification mark is a registered guarantee mark (Garantiemarke) under Swiss trademark law. Organizations wishing to display the mark must: