eVKC SCVE — Self‑Contained Verifiable Capsules

Pack code + data + a manifest into a single capsule, then verify and re‑execute it under policy on another machine.

Simple, predictable, and auditable—aimed at reproducible results, artifact signing, and policy‑guarded execution.

Table of contents

• Why eVKC?
• Quick start (Windows, Python 3.9+)
• Features at a glance
• CLI overview and examples
• Manifest, signing, and sidecars
• Policy and enforcement
• Samples
• Roadmap
• Contributing and support
• License

Why eVKC?

Reproducibility is hard when code, data, and environment drift. eVKC provides a minimal, language‑agnostic container: a zip capsule with a JSON manifest, optional Ed25519 signature, and a policy‑enforced runner. It’s intentionally small and transparent so you can inspect, sign, verify, and re‑run with confidence.

Common use cases:

• Share a deterministic result with verifiable inputs and steps.
• Exchange small, self‑contained research artifacts.
• Execute third‑party capsules with clear safety rails (no network, read‑only, time/memory limits).

Quick start (Windows, Python 3.9+)

Tested with Python 3.11 on Windows. Linux/macOS planned.

# Install from PyPI
pip install evkc

# Optional: create and activate a virtual environment
python -m venv .venv; .\.venv\Scripts\Activate.ps1

# Or install from source (editable dev install)
pip install -e .

# Pack the included sample and produce samples/vqcs.evkc.zip
python -m evkc pack samples/vqcs

# Verify and run under policy (with extra hardening)
python -m evkc verify samples/vqcs.evkc.zip
python -m evkc run --hardened samples/vqcs.evkc.zip

Features at a glance

• Clean JSON manifest: artifacts, entrypoint/steps, and policy in one file.
• Deterministic artifact index: SHA‑256 of each file, generated during pack.
• Optional Ed25519 signing: sign the capsule; verify via sidecar public key.
• Policy‑enforced execution: no‑network, read‑only filesystem, time/memory limits (Windows Job Objects).
• Hardened Python mode: blocks sockets and common HTTP clients inside Python.
• Minimal footprint: inspectable zip archive and sidecar files.

CLI overview and examples

The CLI is available via python -m evkc (or evkc when installed):

• keygen — generate an Ed25519 keypair (base64 .sk and .pk)
• pack — create a .evkc.zip capsule from a folder
• verify — validate manifest, artifact hashes, and signature (if present)
• run — execute a capsule under policy; --hardened enables extra Python‑level protections

Examples:

# Generate signing keys
python -m evkc keygen --out signer

# Pack and sign a sample; also emit the public key sidecar next to the archive
python -m evkc pack samples/vqcs --sign signer.sk --emit-pub

# Verify (requires signature to validate when SIGNER.pub is present)
python -m evkc verify samples/vqcs.evkc.zip

# Run with enforcement and extra Python hardening
python -m evkc run --hardened samples/vqcs.evkc.zip

Minimal manifest example

samples/vqcs/manifest.json (abridged):

{
	"name": "vqcs",
	"version": "0.1.0",
	"description": "Deterministic light-bulb sample",
	"entrypoint": ["python", "simulate.py"],
	"policy": { "network": false, "filesystem_write": false, "max_seconds": 10, "max_memory_mb": 256 },
	"artifacts": [
		{ "path": "simulate.py", "sha256": "..." },
		{ "path": "expected.json", "sha256": "..." }
	]
}

Manifest, signing, and sidecars

• Manifest lives at the root of the folder (manifest.json).
• During pack, missing artifact hashes are generated and written back to the manifest.
• Capsule is a zip archive named <folder>.evkc.zip.
• If signed, sidecars are placed alongside the archive:
  • NAME.evkc.zip.SIGNATURE — raw Ed25519 signature bytes
  • NAME.evkc.zip.SIGNER.pub — raw Ed25519 public key bytes

Policy and enforcement

Policies are enforced by the runner and (optionally) via an extra Python hardening shim:

• network: false — strips proxy env vars; in --hardened mode, blocks sockets/HTTP in Python.
• filesystem_write: false — sets files read‑only and performs pre/post integrity checks.
• max_seconds, max_memory_mb — enforced via Windows Job Objects; processes are assigned to a kill‑on‑close job with limits.

Edge cases handled:

• Timeouts terminate the job (exit code 124).
• Any file mutation under filesystem_write: false fails the run.

Samples

Included sample folders you can pack, verify, and run:

• samples/vqcs — deterministic “light‑bulb” calculation.
• samples/causal_passport — toy deterministic twin check.
• samples/negative_write — attempts to write; verification passes, run fails under policy (expected).

Pack and try one:

python -m evkc pack samples/vqcs
python -m evkc verify samples/vqcs.evkc.zip
python -m evkc run --hardened samples/vqcs.evkc.zip

Roadmap

• Linux/macOS support (cgroups/rlimits and platform‑specific sandboxes).
• Additional policies (CPU affinity, stdout size limits, environment allowlist).
• Optional in‑archive signature block (besides sidecars).
• Richer step orchestration (multi‑step pipelines with typed outputs).

Track progress and file ideas in Issues: https://github.com/Maverick0351a/sCVE-SelfContainedVerifiableEnvironment/issues

Contributing and support

• Linting: Ruff is configured (ruff check, ruff check --fix).
• Dev install: pip install -e ..
• Questions/bugs: open an Issue in the repository.

License

Apache License 2.0 — see LICENSE.