Zero-Cloud Security Whitepaper

Security Architecture & Data Flow Whitepaper

A comprehensive technical breakdown of our client-side differential engine. How we protect sensitive legal, financial, and healthcare documents through mathematical physics rather than corporate policy promises.

Zero Server Ingestion

Document bytes never leave your workstation's physical RAM. No server queues, no cloud buckets, and no temporary disk caches.

WASM Memory Isolation

Tokenization and difference algorithms execute inside an isolated WebAssembly linear memory heap bounded by browser security sandboxes.

Air-Gapped Capable

Operate in completely offline or defense-grade air-gapped environments once static JS/WASM assets are cached in browser memory.

Data Flow Architecture

1. Document Lifecycle & Zero-Transmission Boundary

Contrast how traditional cloud PDF converters process files versus PdfCompare’s local execution model.

LOCAL CLIENT WORKSTATION (Your Browser Runtime)

1. Local File Pick

User selects File A & File B via HTML5 <input> or drag-and-drop

2. In-Memory WASM

FileReader reads binary array buffer; tokenized in browser RAM

3. Local Display

Renders synchronized diff markup & A4 canvases in local DOM

ZERO-NETWORK BOUNDARY • NO DATA CROSSES THIS LINE

PdfCompare Remote Infrastructure (Cloudflare Pages CDN)

Only delivers static web bundles (HTML/CSS/JS/WASM) upon initial page load. Never receives or processes document streams.

Enterprise Risk Analysis

2. Formal Threat Model & Mitigations

How our zero-custody architecture mitigates common enterprise attack vectors:

Threat 1: Cloud Storage Breach or Leaked S3 BucketsMitigated by Physics

Vulnerability: Traditional online tools save uploaded files to cloud databases or temporary S3 buckets where misconfigurations can expose documents to the public.

PdfCompare Mitigation: We do not operate an ingestion database or file server. It is physically impossible for a cloud breach to compromise your documents because we never store them.

Threat 2: Man-in-the-Middle (MitM) Interception on Public Wi-FiZero Network Packets

Vulnerability: An attacker intercepting network packets at an airport or coffee shop could theoretically capture confidential payloads transmitted to a web server.

PdfCompare Mitigation: Because files are loaded directly into local memory via HTML5 File APIs, zero document packets are ever broadcast over Wi-Fi or Ethernet.

Threat 3: Government Subpoenas & Third-Party Disclosure DemandsZero Custody

Vulnerability: Cloud software vendors can be legally compelled to turn over stored customer contracts and audit trails to authorities or opposing litigants.

PdfCompare Mitigation: We cannot comply with requests for customer files because we possess zero customer data. We cannot disclose what we never possessed.

Threat 4: Post-Session Residual Data PersistenceImmediate Garbage Collection

Vulnerability: Web applications might store sensitive file tokens in LocalStorage, IndexedDB, or session cookies that remain accessible after user logout.

PdfCompare Mitigation: PdfCompare writes zero document bytes to persistent browser storage. All document representations exist as volatile JavaScript ArrayBuffers and are immediately dereferenced and purged when the tab is closed.

Independent Audit

3. Self-Verification Guide: How to Verify Us in 60 Seconds

We do not ask you to take our word on trust. You can independently verify our zero-transmission architecture using your own web browser in 5 simple steps:

Step 1: Open Browser Developer Tools

Press F12 or Cmd + Option + I on Mac to open DevTools.

Step 2: Navigate to the "Network" Tab

Select the Network tab and click the Fetch/XHR filter to monitor dynamic API requests.

Step 3: Load Your PDF Documents

Drag and drop your two comparison files into Slot 1 and Slot 2.

Step 4: Execute the Comparison

Click "Compare Differences Now" and inspect the network activity log.

Step 5: Audit the Log (Zero Network Activity)

Notice that exactly 0 requests are sent to any server during the entire differential calculation and export.

4. Regulatory & Compliance Alignment

GDPR (Regulation EU 2016/679)

Under GDPR Article 28, vendors that process personal data on servers require strict Data Processing Agreements (DPAs). Because PdfCompare operates locally on the data subject's device, no personal data is transferred or processed by PdfCompare servers.

HIPAA Security Rule (45 CFR § 164)

Healthcare covered entities must avoid transmitting electronic Protected Health Information (ePHI) to unauthorized vendors. Because no data is transmitted across public networks to PdfCompare, ePHI stays within the covered entity's secure perimeter.

Security & Privacy Frequently Asked Questions

Common questions from Chief Information Security Officers (CISOs), attorneys, and IT auditors.

Do you ever upload my PDF files to a server?

No. Never. Our application is architected so that all document ingestion, parsing, diff calculation, and visual rendering happen entirely inside your web browser's local JavaScript/WebAssembly memory sandbox. No PDF bytes are ever transmitted over the network.

How can I verify that my files aren't being sent over the network?

You can independently verify this using your browser's built-in developer tools. Open Chrome DevTools (Press F12), go to the Network tab, filter by Fetch/XHR, and upload your documents. You will observe exactly zero outbound network requests during file parsing and difference calculations.

Can I use PdfCompare completely offline or in an air-gapped environment?

Yes. Once the web page assets are loaded in your browser, you can disconnect your internet connection (or turn on Airplane Mode) and the PDF comparison engine will continue to run without interruption.

What happens to my document data when I close the browser tab?

All temporary memory buffers (ArrayBuffers and Canvas bitmaps) reside strictly in volatile RAM. The moment you close or refresh the browser tab, the operating system and browser runtime immediately deallocate and garbage-collect those memory segments. Nothing is persisted to local storage or cookies.

Does PdfCompare require a Business Associate Agreement (BAA) for HIPAA compliance?

Because PdfCompare never receives, transmits, processes, or stores Protected Health Information (PHI) on its servers, PdfCompare does not act as a Business Associate under HIPAA rules. Document data never leaves your covered entity's workstation, eliminating third-party custody liabilities.

Are the open-source libraries used in PdfCompare auditable?

Yes. The core PDF rendering and manipulation relies on battle-tested, open-standard libraries such as Mozilla's pdf.js and pdf-lib, which are publicly auditable and widely deployed across global enterprise software.

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