Secure SSH Jail / Chroot Consulting

SSH jails (chroot + internal-sftp) provide the strongest isolation for internet-facing SSH access — perfect for secure file drops, log collection, or single-purpose command execution without risking the host system. Zwiegnet designs and implements ultra-secure, key-only SSH jails that survive brute-force, credential theft, and key compromise scenarios.

Our SSH jail services include:

• Chroot Jail Design & Setup – Create locked-down chroot environments with internal-sftp, minimal filesystem, and strict ownership/permissions.
• Key-Only Authentication Enforcement – Disable passwords entirely, deploy ed25519 keys, automate key rotation, and enforce authorized_keys restrictions.
• ForceCommand & Subsystem Lockdown – Force internal-sftp, disable shell, block port forwarding, X11, and tunneling for zero shell escape risk.
• Security Hardening & Attack Mitigation – Port knocking, fail2ban integration, rate limiting, allow-from-IP restrictions, and modern ciphers/KEX/MACs only.
• High Availability & Bastion Hosts – Build secure bastion/jump hosts with jailed SSH, load balancing, and failover for enterprise access.
• Auditing & Monitoring – Verbose SSH logging, auditd integration, centralized syslog, and real-time alerts for login attempts or anomalies.
• Migration & Modernization – Transition legacy SSH to jailed setups, migrate keys/certificates, and integrate with modern IAM (LDAP/Kerberos/RADIUS).
• Troubleshooting & Recovery – Diagnose chroot failures, permission issues, key problems, and rapid recovery from misconfiguration.

Ideal for: financial institutions, healthcare providers, SaaS platforms, managed service providers, and any organization needing secure, auditable, limited SSH access over the internet without exposing the full system.

Located between Madison and Milwaukee, Wisconsin since 2009 — direct access to SSH security specialists with proven experience in ultra-hardened, internet-facing configurations.