Kryptor is a free, open-source file encryption and signing CLI for Windows, Linux, and macOS. It uses modern primitives via libsodium (XChaCha20-Poly1305, Argon2id, Ed25519) with no configuration options and encrypts file names optionally.
Reviewed by Marcus Holmberg
Kryptor
kryptor.co.uk 1 rating so far*
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Threat level
Hardened
A hardened pick. Worth the effort once you have chosen to shrink your footprint on purpose. Enough for most people. Threat levels
Our take
Kryptor takes a principled stance on cryptographic agility by offering exactly one algorithm suite with no config knobs, which is how modern tools should work. The protocol is documented in enough detail to audit independently, and the encrypted output is indistinguishable from random, which limits metadata leakage. It is a solo-maintained project rather than a large community effort, so the pace of updates is unhurried. If you want a leaner, more modern alternative to GnuPG for file encryption and signing on the command line and you are not tied to the OpenPGP ecosystem, Kryptor is a thoughtful choice.
GitHub at a glance
samuel-lucas6/Kryptor GPL-3.0 argon2idblake2bchacha20-poly1305clicryptographycurve25519digital-signaturesed25519elligator2encryptionfile-encryptionlibsodiumlinuxmacosmonocypherportablesignaturessigningwindowsx25519
Stars
510
+2 this week
Forks
32
14 watching
Last commit
1.8y ago
slowing
Latest release
v4.1.1
1.8y ago, 18 total
Star history
Issues
100% closed
0
open
27
closed
+0 / -0
opened / closed, last 4 weeks
Opened vs closed, last 12 weeks
Commits, last 26 weeks
0 commits, active 0 of 26 weeks
2 contributors since Aug 2020
Languages
- C# 100%
Updated daily from the GitHub API. Star tracking since Jun 22, 2026.
Website at a glance
kryptor.co.uk
B score 70
Solid website security headers
Graded by Mozilla HTTP Observatory, tested 4d ago
Inspect this site yourself
Measures the security configuration of the tool's own website, not the privacy of the product itself. A strong tool can still score low here.
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BitLocker BitLocker is the built-in full-disk encryption feature in Windows Pro, Enterprise, and Education editions. It encrypts the operating system drive and fixed data drives using AES-XTS, with optional TPM-backed pre-boot authentication.
VERNAM A free, fully client-side file encryptor that runs in your browser. Drop in any file, set or generate a passphrase, and it seals the result into its own .vrn format. Nothing is ever uploaded, and it works offline.
VeraCrypt It can create a virtual encrypted disk that works just like a regular disk but within a file. It can also encrypt a partition or the entire storage device with pre-boot…
Kryptor license, in plain English
GPL-3.0 Strong copyleft
Free to use and modify, but anything you distribute that is built on it must also be open under the same license.
Permits
- Commercial use
- Modification
- Distribution
- Patent use
- Private use
Requires
- Disclose source
- Same license
- State changes
- License and copyright notice
Does not provide
- Liability cover
- Warranty
Why it matters: Strong copyleft keeps every distributed version open. A vendor cannot fold this into a closed product and ship it without releasing their changes.
Plain-language summary of the project's license, not legal advice. Read the full text for the exact terms.
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