Executive Summary
Everything is hackable, unless it is not worth the cost and time.
This proof-of-concept demonstrates a hardened SSH server built with defense-in-depth principles, including Cryptoagility, Zero Trust Zero Tolerance, and modern cryptographic best practices.
The configuration has been evaluated by Perplexity AI against sophisticated real-world threat scenarios (supply chain compromise, nation-state MITM, private key theft, and future quantum threats). The independent assessment concludes that successful compromise requires extraordinary resources — typically millions of dollars and/or centuries of compute time — making the system practically unhackable for all realistic threat actors.
Defensive Techniques
| Technique | Purpose | Maturity |
|---|---|---|
| Memory-hard KDF | Protects passphrases against offline brute-force (GPU/ASIC) | Exceeds Standards |
| DNSSEC + SSHFP Records | Cryptographically validates host keys to prevent spoofing/MITM | Meets Standards |
| Modern Elliptic Curve Host Keys | High-security, high-performance signatures | Meets Standards |
| Login Throttling & Permanent Bans | Rate-limits online guessing attempts | Meets Standards |
| Hybrid Post-Quantum Key Exchange | Dual-layer protection (classical + quantum-resistant) | Advanced / Cryptoagility |
| Monthly Key Rotation | Limits exposure window to 30 days maximum | Operational Control |
| No Direct Root Login | Forces attackers through privilege escalation path | Meets Standards |
| Strong Privilege Escalation Controls | Memory-hard hashing for sudo | Exceeds Standards |
Threat Scenarios & Feasibility
| Scenario | Required Investment | Feasibility |
|---|---|---|
| Supply Chain / Public Key Theft | $2.5M – $8M+ | Very Low |
| ISP/CSP Man-in-the-Middle (MITM) | $3M – $20M+ | Very Low |
| Private Key Theft (no passphrase) | $4B+ (or centuries of compute) | Very Low |
All scenarios are independently protected by multiple distinct layers, making simultaneous compromise economically and technically infeasible for non-nation-state actors.
Bug Bounty Program
Reward: $1,000 USD (paid personally by the owner)
Scope: In-scope: SSH server only
Out-of-scope: DoS/DDoS, social engineering, physical attacks, other services on the domain
Rules:
- Responsible disclosure only
- No destructive testing
- Do not exploit any vulnerability beyond proof-of-concept
- Provide clear reproduction steps
Safe Harbor: Good-faith security research within the scope above will not result in legal action.
To report: Use the contact form on the homepage or email the address listed there.
Next Steps
Future iterations will intentionally expand the attack surface by adding more services to further test the resilience of the model.
Status: Live since January 2026