ESIGN & UETA Compliant
eIDAS-Aligned
GCP Hardened Security

Enterprise-Grade Signatures. Startup-Friendly Pricing.

Join 500+ teams automating document logistics with ephemeral security, 60% average cost savings, and 100% data sovereignty.

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Assess Risk2-min Security Audit
500+
Integrated Teams
10M+
Hardened Documents
60%
Average Efficiency Gain
4.9/5
Peer Review Average
IUSign Core Interface
IUSign Signing Interface
IUSign Control Center

Scale Document Logistics

Enterprise-grade visibility

Crypto-Chain Audit Log

Immutable Provenance

SHA-256 Chain Integrity

Engineered to outperform.

Swipe to compare
Capability FrameworkIUSignLegacy Vendor DLegacy Vendor S
Bulk Send Pipeline
Built-in / Unlimited
NoLimited
Domain White-labeling
Standard / Native
Enterprise OnlyNo
API Ecosystem
Developer-First / Full
Restricted / TieredRestricted
Envelope Surcharge
Non-existent
Usage-based FeesUsage-based Fees
GCP KMS Key Control
Included / Native
UnavailableUnavailable
Cryptographic Provenance
SHA-256 Chaining
NoneNone
Assess Risk

Current Feature Matrix Verification: April 2026

Core Ecosystem

Full Stack. Zero Bloat.

Visual Document Preparation

Drag-and-drop signature, text, date, and checkbox fields directly onto your PDF. Upload PDF or DOCX — automatic conversion via LibreOffice.

Sequential Multi-Party Signing

Define signing order: Person 1 → Person 2 → Person 3. Each signer receives the document only when it's their turn.

Immutable Audit Trail

Database-level triggers physically prevent deletion or modification of audit logs. SHA-256 hash chain per event.

Change Request & Revision Workflow

Signers click anywhere on the PDF to place comment pins. You resolve, upload a revised document, and re-send — all version-tracked.

Full White-Label Capability

Custom logo, brand colors, organization name, custom email from address, custom domain with DNS verification. Per-tenant usage limits enforced.

Smart Email Delivery

Redis-backed queue with exponential backoff retry. 4 Jinja2 email templates with custom composer and variable substitution.

Stuck Document Detection

Automatically detects documents inactive for 7+ days. Status filters, manual reminders, and blocker identification.

Developer API & SDK

39 documented endpoints. Postman collection, Python SDK, Swagger UI, HMAC-signed webhooks with retry, idempotency support.

Secure by Architecture

Infrastructure-Level Trust

AES-256-GCM GCP KMS Envelopes

Your document is encrypted with a unique data encryption key (DEK) before it ever touches disk. The DEK itself is wrapped with a master key controlled in your GCP KMS instance.

Deploy Control Key
IUSIGN_KERNEL_X64
// GCP KMS ENVELOPE HANDSHAKE
STATUS: ENCRYPTED
MASTER: kms:global:ias:key/01
DEK_HASH: sha256:5e8...3a2
// ACCESS LOGGED VIA CLOUD AUDIT ✓

SHA-256 Hash Chain Integrity

Every signature event — envelope created, document viewed, signature applied — is cryptographically chained. If a single record is altered, the entire chain triggers a violation.

Validate Integrity
IUSIGN_KERNEL_X64
// CRYPTO-CHAIN VERIFICATION
EVENT: SIG_LOG_09
SIGNED_BY: MICHAEL ROBERTS
HASH: 0x82f0be...a12b
PREV: VIEW_LOG_08
DOCUMENT_RENDERED
HASH: 0x41e9d4...d94c
INTEGRITY: MATHEMATICALLY VERIFIED ✓

Ephemeral Zero-Persistence Flow

Raw document content exists only in temporary memory buffers during processing. We physically collect garbage (GC) and overwrite memory sectors after encryption.

Simulate Breach
IUSIGN_KERNEL_X64
// ZERO-PERSISTENCE STREAM
... allocating ephemeral_buffer [0x00FF23]
input_stream = io.BytesIO(encrypted_blob)
transformer.flatten(input_stream)
! EMERGENCY WIPEOUT INITIATED !
overwrite_sectors(0x00FF23, pattern=0x00, passes=3)
SOVEREIGNTY PRESERVED ✓

Immutable PDF Flattening

Signatures aren't just invisible overlays; they are physically burned into the document's structure at 300 DPI, creating a permanent, flattened forensic record.

Verify Provenance
IUSIGN_KERNEL_X64
IUSIGN ARCHITECTURE VERIFICATION
PROCESS_ID: 71675
status = service.verify("pdf-render")
Result: SUCCESS -- ENFORCED

Universal Evidence Package

Export a self-contained, court-ready JSON bundle containing all metadata, signer IP logs, intent capture, and the full hash chain provenance.

Download Bundle
IUSIGN_KERNEL_X64
IUSIGN ARCHITECTURE VERIFICATION
PROCESS_ID: 32058
status = service.verify("evidence-json")
Result: SUCCESS -- ENFORCED

HMAC-Signed Idempotent Pipelines

Webhooks aren't just POST requests. They are HMAC-signed for security and support idempotent retry logic to ensure your backend stays in perfect sync.

Test Endpoint
IUSIGN_KERNEL_X64
IUSIGN ARCHITECTURE VERIFICATION
PROCESS_ID: 79575
status = service.verify("webhook-flow")
Result: SUCCESS -- ENFORCED

Common Queries

Everything you need to know.

Is IUSign legally binding?

Yes. IUSign is fully compliant with the ESIGN Act and UETA in the US, and aligns with eIDAS standards in the EU. We capture intent to sign, mandatory consent, and provide an immutable SHA-256 audit trail for every transaction.

How does the 'Zero-Persistence' security work?

Unlike traditional platforms, IUSign processes sensitive document data in ephemeral memory. Once the PDF is flattened and encrypted, the raw data is physically overwritten in memory, ensuring your document content is never stored in an unencrypted state.

Can I use my own domain for signing?

Absolutely. Our Growth plan includes full white-labeling, allowing you to use your own domain (e.g., sign.yourcompany.com) with automated SSL, custom email branding, and localized signing experiences.

What is an Immutable Audit Trail?

Every event in the signing process is cryptographically hashed and chained to the previous event. This creates a forensic record that cannot be altered without detection, ensuring absolute cryptographic certainty in a court of law.

Does IUSign have a developer API?

Yes. We pride ourselves on being developer-first. We offer 39 documented REST endpoints, Python and Node.js SDKs, HMAC-signed webhooks, and a sub-15 minute integration time for most applications.

Take control of your document logistics.

Self-hosted ephemeral security, immutable audit trails, and 100% data sovereignty starts here.

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