Use Case Analysis

Purpose

This document provides an overview of primary use cases for AirGap Transfer, a tool for safely transferring large files and datasets across air-gap boundaries using removable media.

User Personas

IT Administrator

  • Needs: Move deployment packages and updates to air-gapped servers

  • Environment: air-gapped data centers, secure facilities

  • Priority: Reliability, verification, clear progress reporting

Data Scientist / Researcher

  • Needs: Transfer large datasets (ML models, experiment data) to isolated compute

  • Environment: Research lab with air-gapped GPU cluster

  • Priority: Handle multi-GB files, resume interrupted transfers

Security Operations Staff

  • Needs: Move patches, tools, and forensic data across security boundaries

  • Environment: Government, military, or compliance-sensitive infrastructure

  • Priority: Integrity verification, chain-of-custody support, audit trail

Field Technician

  • Needs: Deliver software updates to remote air-gapped installations

  • Environment: Industrial control systems, remote sites with limited USB capacity

  • Priority: Multi-USB coordination, simple CLI, error recovery

Workflow Use Cases

Happy-path scenarios covering the core pack → transfer → unpack workflow across different data sizes and transfer configurations.

Large File Transfer

Scenario: Transfer a single large file (e.g., VM image, video file) that exceeds USB drive capacity.

Key Requirements:

  • Split file into chunks

  • Verify integrity after reconstruction

  • Resume if interrupted

Use Case: Large File Transfer

Large Directory Transfer

Scenario: Transfer a directory containing many files (e.g., dataset, codebase) across air-gap.

Key Requirements:

  • Preserve directory structure

  • Handle mixed file sizes efficiently

  • Batch verification

Use Case: Large Directory Transfer

Multiple USB Workflow

Scenario: Transfer dataset larger than any single USB drive, requiring multiple USB drives.

Key Requirements:

  • Coordinate multiple USBs

  • Track which chunks are on which USB

  • Resume with any available USB

Use Case: Multi-USB Dataset Transfer

SBOM Transfer (v1.1)

Scenario: Transfer a deployment package containing a CycloneDX SBOM, with automatic SBOM detection and audit trail logging.

Key Requirements:

  • Detect SBOM in transfer manifest

  • Log SBOM presence in audit trail

  • Chain-of-custody documentation

UC-TRANSFER-004

Diagnostic & Operational Use Cases

Scenarios focused on inspection, verification, and pre-transfer checks — what operators do before committing to an unpack.

Verify Transfer Integrity

Scenario: Operator receives USB drives and inspects chunk inventory, checks checksums, and identifies missing or corrupted chunks before unpacking.

Key Requirements:

  • Display chunk inventory and sizes

  • Identify missing chunks

  • Verify checksums against manifest

Use Case: Verify Transfer Integrity

Error Recovery & Safety Use Cases

Scenarios covering what happens when things go wrong — interrupted operations, insufficient space, accidental overwrites — and how the tool helps operators recover safely.

Recover from Transfer Failure

Scenario: Pack or unpack is interrupted by insufficient USB space, power loss, or missing chunks. Operator uses resume to recover.

Key Requirements:

  • Manifest-based state tracking

  • Resume from last completed chunk

  • Clear error messages with recovery hints

Use Case: Recover from Transfer Failure

Protect Against Data Loss

Scenario: Operator accidentally targets a directory with existing files. The tool’s safety features prevent silent overwrites.

Key Requirements:

  • Overwrite protection by default

  • Explicit --force opt-in

  • Safe USB synchronization before ejection

Use Case: Protect Against Data Loss

Common Requirements Across All Use Cases

Requirement

Rationale

Checksum verification

Ensure data integrity across air-gap boundary

Resume capability

Handle interruptions without data loss

Progress reporting

User awareness during long operations

Dry-run mode

Preview operations before execution

Clear error messages

Guide user through recovery procedures

Integration with AirGap Deploy

AirGap Transfer is designed to integrate with the AirGap Deploy project for complete air-gap deployment workflows:

  • AirGap Deploy: Orchestrates overall deployment process, prepares packages

  • AirGap Transfer: Handles chunked data transfer when packages exceed USB capacity

  • Cleanroom Whisper: Example application deployed using AirGap Deploy

See: AirGap Deploy workflow examples

Out of Scope

The following are explicitly NOT supported in MVP:

Use Case

Why Not in MVP

Real-time sync

Requires complexity beyond MVP scope

Network transfer

Violates air-gap design principle

Automatic USB hot-swap detection

Hardware-dependent, defer to post-MVP

Compression during transfer

Adds complexity, defer to post-MVP

Encryption

Planned for v1.2 (AEAD + key derivation)

Success Metrics

Metric

Target

Transfer accuracy

100% (verified by checksums)

Resume success rate

> 95% (interrupted transfers)

User errors

< 5% (clear guidance prevents mistakes)

Cross-platform compatibility

macOS, Windows, Linux