RemoteRails Security Model: Confidential Computing & Defense in Depth

At RemoteRails, we employ a comprehensive, defense-in-depth security architecture designed to protect your data across all states: at rest, in transit, and in use. From baseline hardware protections to advanced confidential computing environments, our infrastructure ensures isolated, verifiable, and highly secure operations.

Advanced Threat Mitigation: Live Server Seizures

A highly sophisticated physical attack involves a “live seizure” or “hot extraction,” where an attacker uses a mobile uninterruptible power supply (UPS) cart to physically remove a server from a datacenter rack while keeping it powered on. This attempts to bypass standard “power-off” disk encryption. Our architecture defends against this via:

  • Transparent Memory Encryption (SME/TME): Physical memory modules are encrypted in real-time. If an attacker attempts to logically dump, physically probe, or freeze the RAM on the live machine, the memory contents remain unintelligible ciphertext.
  • Hardware IOMMU Controls: Direct Memory Access (DMA) attacks are neutralized. An attacker cannot plug in a malicious peripheral (such as a compromised PCIe network card or a rogue Thunderbolt device) to scrape live memory over the hardware bus.

Baseline Appliance Security

These protections are standard across all RemoteRails appliances – starting from the Cloud / VPS tier and up.

Security MeasureTechnology / ImplementationThreat Defended Against
Full Disk EncryptionLUKS2 (argon2id) encrypted storageProtects data at rest if drives are physically pulled, forensically examined, or improperly disposed of.
Remote Boot UnlockingDropbear Initramfs via SSH (port 2222)Halts pre-boot sequence until a passphrase is provided remotely, preventing unauthorized boots if an appliance is seized while powered off.
Container IsolationLeast PrivilegeApplication containers are restricted to regular (non-root) user permissions wherever possible. Containers are explicitly granted system capabilities on the host machine where required.

Dedicated Deployments & Bare Metal

Advanced protections included with both our Dedicated Bare Metal and Hypervisor tiers.

Security MeasureTechnology / ImplementationThreat Defended Against
Physical IsolationSingle TenancyEliminates cross-tenant, side-channel attacks theoretically possible on shared physical hypervisors.
Verified Boot SequenceSecure Boot & EFI Mirroring with sbctl keysEstablishes a secure chain of trust preventing rootkits. Mirrored across root drives for operational resilience.
Memory ProtectionIOMMU (AMD Vi / Intel VT-d)Blocks Direct Memory Access (DMA) attacks by unauthorized physical peripherals (e.g., malicious PCIe cards or Thunderbolt devices).
Memory EncryptionSME/TSME or TME (Secure / Total Memory Encryption)Transparently encrypts system RAM, protecting against live memory probing and cold-boot physical analysis.
Storage ResilienceRAID Arrays with LVM Safety MarginsPrevents LVM Thin-Pool auto-extension lockups and VM data corruption during high I/O virtualization loads.
Crypto-ShreddingHardware Vaporization (wipefs + blkdiscard)Destroys LUKS headers/superblocks and continuously flushes SSD NAND cells for absolute data destruction during emergency resets.
Bootloader BypassUnified Kernel Image (UKI) via systemd-ukifyBypasses GRUB completely by wrapping the kernel and keys into a single signed binary. Secures against physical “Evil Maid” attacks.

Advanced Confidential Computing

The highest level of isolation – available exclusively as an optional add-on for Dedicated Hypervisor deployments – on supported server hardware with AMD SEV-SNP or Intel TDX. The virtual machine boundary provided by Proxmox is required for these Confidential Computing features at the silicon level to have any practical effect.

Security MeasureTechnology / ImplementationThreat Defended Against
Hardware-Enforced VM IsolationAMD SEV-SNP & Intel TDXCryptographically isolates VM operating memory from the Proxmox hypervisor and other VMs, shifting the root of trust strictly to the CPU.
Measured Boot & AttestationHardware-backed UKI VerificationBuilds upon the UKI to provide absolute mathematical proof (cryptographic attestation) of software integrity before sensitive data is decrypted and processed.

By layering these hardware, cryptographic, and software-level protections, this defense-in-depth model makes it possible to safely deploy a highly confidential appliance directly within a commercial datacenter. This unique architecture affords you the absolute, “on-premise-like” security necessary for extremely sensitive workloads, while seamlessly allowing you to leverage the immense cost-efficiency, scale, and performance of dedicated host hardware.