Full-disk encryption is the default answer to "how do I protect my data at rest", and for one specific threat it is exactly right. Turn the laptop off, lose it in a taxi, and the drive is unreadable.
Now log in. Everything is decrypted again.
That is not a flaw in BitLocker or FileVault — it is what full-disk encryption is designed to do. But if you think "I enabled FileVault, so my files are encrypted", you have a gap, and the gap is the entire time your machine is switched on. Which is the only time anyone can actually steal anything from you remotely.
The fix is not a better tool. It is understanding that "encryption at rest" is three different problems wearing one name.
Three layers, three threat models
| Layer | Protects against | Useless against |
|---|---|---|
| Full disk | Lost/stolen powered-off device | Anything after you log in |
| File / archive | Exfiltration of specific files, cloud sync leaks, email attachments | Whole-device seizure while running |
| Pre-upload cloud | Provider-side access, compromised cloud account, provider breach | Someone with your plaintext and your keys |
Pick the wrong layer and you get encryption that audits well and protects nothing.
Layer 1: Full disk — the powered-off guarantee
The native options are good and free: BitLocker on Windows 10/11 Pro, Enterprise and Education (AES 128/256, tied to the TPM so boot integrity is checked before decryption), and FileVault on macOS. Both are closed-source, so you are trusting the vendor's implementation.
VeraCrypt is the open-source alternative, and it is the one I would point at for anything that matters. It does AES, Serpent, and Twofish — individually or cascaded — runs on Windows, macOS and Linux, and inherits TrueCrypt's lineage with the brute-force cost fixed by massively raising PBKDF2 iterations.
It also does a thing the others do not: hidden volumes. A hidden volume lives in the free space of a normal VeraCrypt volume and is indistinguishable from random noise. If you are compelled to hand over a password, you hand over the outer one, and the existence of the inner volume is not provable. You may never need it. It is nice that the option exists in a tool you can read the source of.
Layer 2: File and archive — the one people skip
This is where the running-machine gap gets closed, and it is where most setups I see are empty.
- GPG (GnuPG) for files and email. Free, open source, and the closest thing to a universal answer for "encrypt this one thing and send it to someone".
- 7-Zip for encrypted archives — compressing and encrypting in one step, which is usually what you actually want before a file leaves your machine.
- AxCrypt if you want file-level encryption without living in a terminal (free tier, or about $3.75/month).
The decision here is not which tool is strongest. It is what are you willing to type a passphrase for every single time. Tools you do not use provide no security.
Layer 3: Before it hits the cloud
Cryptomator is the interesting one, because it changes when encryption happens: files are encrypted on your device, then uploaded. The provider only ever holds ciphertext.
That single architectural choice removes an entire category of risk — provider-side access, a breached provider, a hijacked cloud account — because none of those give an attacker anything readable. Compare that to "my cloud provider says they encrypt at rest", which protects you from a thief walking out with a hard drive and from nobody else.
The auditability question
Of the seven tools in the full comparison, five are open source: VeraCrypt, AxCrypt, 7-Zip, GPG, Cryptomator. Two are not: BitLocker and FileVault.
I am not going to tell you the closed-source ones are unsafe — BitLocker's TPM integration is genuinely valuable and FileVault is well regarded. But "I cannot read the code" is a real property of a system, and for the layer protecting your data while it is powered off, being able to check is worth something.
What I would actually do
- Full disk on, always. BitLocker or FileVault, no excuses — it is free and it covers the lost-laptop case completely.
- Add a file layer for the small set of things that would actually hurt. Not everything. The 20 files where exfiltration is a real event.
- Encrypt before upload, not after. If it is going to someone else's disk, Cryptomator or GPG before it leaves yours.
Most people do step one and stop. Step one is the one that protects you when nothing is happening.
Full comparison of all seven tools, with pricing, platform support and per-tool trade-offs: cyberpicks.org
Originally published at CyberPicks.
What does your setup look like — full disk only, or do you actually have a file layer? I suspect I know the answer, and I suspect it is the same as mine was.
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