Encrypted backup
we mathematically cannot read

Most "encrypted" backup services hold the key alongside your data. ServerCrate doesn't. Your files are encrypted on your machine before they leave it, with a key only you possess. We store ciphertext we cannot decrypt - not by policy, by mathematics. If we get subpoenaed, breached, or acquired, your data stays unreadable.

Why ServerCrate

Three things nobody else combines.

Restic-native, not Restic-compatible

Built for Restic from day one. Borg works too, but Restic is the default voice. BorgBase is Borg-first. We're the inverse.

ZFS-backed and we say so

Every vault sits on ZFS with checksumming and snapshots. Bit rot on a 3-year-old archive gets caught. Most providers won't tell you their backend.

US West Coast hosting

Single Los Angeles datacenter. Low latency for North American users. BorgBase is EU-only. rsync.net is multi-region but priced for it.

The Problem With Most "Encrypted" Backup Services

When a backup service says your data is "encrypted," it usually means one of two things: the data is encrypted in transit (TLS), or the data is encrypted at rest on their servers using a key they manage. In both cases, the service provider can decrypt your data - either while it's in transit or by using the key they control.

This is sometimes called "server-side encryption" and it provides almost no meaningful privacy protection. It protects against a disk being stolen from a data center, but not against the company reading your data, responding to subpoenas, or a breach of their key management systems.

True encrypted backup requires that the encryption key never leaves your machine - often called "zero-knowledge" or "client-side" encryption. ServerCrate uses Restic, which implements this correctly.

How Zero-Knowledge Encryption Works in ServerCrate

When you run a Restic backup to ServerCrate, the following happens entirely on your machine before any data is transmitted:

  • Restic reads your files and splits them into variable-size chunks using content-defined chunking
  • Each chunk is encrypted using AES-256-CTR with a key derived from your repository password
  • The encrypted chunks are then transmitted over SFTP to your ServerCrate vault
  • ServerCrate stores only the encrypted chunks - meaningless data without your key

The repository password (your encryption key) is never sent to ServerCrate. It never appears in any log, request, or storage on our infrastructure. Even if ServerCrate were fully compromised, your data would remain inaccessible to an attacker.

What "Zero-Knowledge" Actually Means

Zero-knowledge is a precise technical term. A zero-knowledge encrypted backup service is one where the service provider has zero knowledge of the contents of your backups - not zero knowledge as a marketing claim, but as a mathematical property of the system.

ServerCrate achieves this through Restic's encryption model. The encryption key is derived from your repository password using PBKDF2. The master key is then used to encrypt a randomly generated encryption key that protects your data. This key is stored encrypted in the repository itself - only your password can unlock it.

This means we could hand over every byte of your vault storage to any third party and it would be useless without your password. That is not a policy promise - it is a cryptographic fact.

Encrypted Backup for Different Workloads

Linux servers and VPS instances

Run Restic from a cron job or systemd timer to back up /home, /etc, /var, application data, and database dumps. Every backup run creates an encrypted snapshot. Restore specific files, directories, or entire snapshots without egress charges.

Homelabs and Proxmox environments

Back up VM configs, Docker volumes NAS data, and critical scripts to an encrypted offsite vault. ZFS-backed storage means your backup repository stays consistent over time. See the homelab backup guide for specific workflows.

Developer workstations and laptops

Restic runs on macOS and Windows as well as Linux. Back up your development environment, project files, dotfiles, and local databases to an encrypted offsite vault. Restore to a new machine in minutes.

Privacy-sensitive personal data

Photos, documents, financial records, and anything you want to keep private. Client-side encryption means your data stays private regardless of what happens on the server side. No scanning, no indexing, no analysis.

Comparing Encrypted Backup Services

When evaluating encrypted backup services, the key question is: who holds the encryption key? Here is a quick breakdown:

  • ServerCrate / Restic:You hold the key. Zero-knowledge by cryptographic design.
  • Backblaze B2:Server-side encryption managed by Backblaze. They can decrypt your data.
  • Dropbox / Google Drive:Provider-managed encryption. Provider has full access.
  • iDrive:Optional client-side key, but proprietary client required. Less auditable.
  • BorgBase:Supports Borg and Restic. Both use client-side encryption. Strong option for Borg users.

ServerCrate and BorgBase are the two services that provide genuine zero-knowledge encrypted offsite backup for technical users. The primary differences are in pricing structure, storage infrastructure, and target workflow. See the ServerCrate vs BorgBase comparison.

Pricing

ServerCrate uses flat monthly pricing with no egress fees. You pay one price and restore your encrypted backups as many times as you need.

  • Free:10 GB, 1 device, 7-day retention - no credit card
  • Starter ($5/mo):200 GB, 1 device, 30-day retention
  • Standard ($15/mo):1 TB, 3 devices, 60-day retention
  • Pro ($29/mo):2 TB, 5 devices, 90-day retention

How your data flows, step by step

This is what happens when you run restic backup against a ServerCrate vault. Every step is engineered to give us zero visibility into your actual data.

Step 1: Restic scans your files locally
Restic walks the directory tree on your machine, reads each file, and splits it into content-defined chunks of ~1-8 MB. Chunks are identified by their SHA-256 hash.
Step 2: Each chunk is encrypted with your repository key
AES-256 in CTR mode, with a Poly1305-AES MAC for authentication. The key is derived from your password via scrypt (a memory-hard KDF that resists GPU brute-forcing). Everything happens in process memory on your device. The plaintext never leaves.
Step 3: Encrypted chunks upload via SFTP over SSH
The SFTP transport is wrapped in SSH, which adds a second layer of encryption-in-transit. Even if someone intercepted the traffic (they can't), they'd see TLS-style encrypted streams carrying already-encrypted chunks.
Step 4: ServerCrate stores opaque ciphertext on ZFS
From our perspective, your vault fills up with files named like data/ab/cdef1234... - opaque content-addressed blobs. We can see that you're storing data. We can't see what. File sizes are randomized within Restic's chunk size range, so even size-based inference attacks are limited.
Step 5: Snapshots are lightweight metadata pointers
A "snapshot" in Restic is just a small signed reference to the tree of chunks it contains. Multiple snapshots share chunks at the storage layer (deduplication), so a daily backup set of 30 snapshots isn't 30x the storage - it's only as large as the unique data across all of them.

What "zero-knowledge" actually rules out

The term gets marketed loosely. Here's what it means concretely for ServerCrate:

We cannot read your file contents

The data is AES-256 encrypted before it leaves your machine. Without your password, the stored bytes are mathematically useless. Not "legally protected" or "policy-restricted" - actually impossible.

We cannot see filenames or directory structure

Filenames live inside Restic's encrypted metadata trees, not as filesystem objects. We see content-addressed blobs on disk, nothing that reveals "user has a file called resume-final-v3.pdf in their Documents folder."

We cannot help you if you lose your password

This is the critical tradeoff. Real zero-knowledge means no server-side key escrow. If you lose your Restic repository password, your data is cryptographically lost. That's the same promise that makes the system secure against us.

Mitigation: Store your password in a real password manager (1Password, Bitwarden, KeePassXC) and ensure someone you trust has recovery access. Don't tattoo it on your forearm, but treat it with that level of seriousness.

We can tell you the size of your vault and how old snapshots are

Billing and monitoring require metadata. We see bytes stored, vault activity timestamps, and connection source IPs. We do NOT see file counts, specific filenames, or file timing patterns that would leak intelligence about what's in your backups.

Encryption doesn't replace the other security basics

Zero-knowledge encryption is one layer. For a complete setup, also:

  • Enable 2FA on your ServerCrate account.Prevents someone who phishes your password from logging into the portal and removing your vault. Note: this doesn't protect your data (encryption already does that), it protects your account.
  • Use a strong, unique Restic repository password.20+ characters from a password manager. This is the key that protects your actual data - weak password = weak encryption in practice.
  • Store your password in at least two independent places.Password manager + printed copy in a safe + a trusted family member with instructions. If you're the only person who knows it and you're hit by the proverbial bus, your backups are inaccessible.
  • Test restores quarterly.A backup you've never restored from isn't a backup, it's a hope. Use restic mount or restic restore --target /tmp/test every 3 months to verify everything still works.
Zero-Knowledge by Design
The encryption happens
before we see anything.

Restic encrypts your data locally using a key derived from your password. The encrypted chunks are then transmitted to your ServerCrate vault. We store only ciphertext.

AES-256-CTR encryption
Key derived locally via PBKDF2
Encryption key never transmitted
Open-source Restic client - auditable
Dedicated private vault per user
ZFS data integrity verification
No scanning or content analysis
No egress fees on restore

Start your encrypted backup today

Free plan includes 10 GB. No credit card. Vault provisions in seconds after email verification.

Start Free - 10 GB forever, no card Setup Guide

Bitcoin-friendly: We accept on-chain BTC and Lightning via self-hosted BTCPay. See Restic backup paid with Bitcoin for the full breakdown.

Next steps
How we protect your data
Zero-knowledge encryption, ZFS isolation, what we log
Who runs ServerCrate
Operating commitments, where data lives, transparency
First backup in 5 min
Sign up, init vault, run your first Restic backup
All 5 plans

Flat monthly pricing. No egress fees.

  1. Free10 GB · forever
  2. Starter200 GB · $5/mo
  3. Standard1 TB · $15/mo
  4. Pro2 TB · $29/mo
  5. Business5 TB · $79/mo
See full pricing →