Cryptographic ID

F-Droid Open Source | Security

6 Downloads 14 Views v0.5 52.18 MB 4.1+

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(52.18 MB)

Editor's Overview

Cryptographic ID is a security application developed by F-Droid Open Source, packaged as a single Android APK of version 0.5 weighing in at 52.18 MB. The package targets Android 4.1+ and above. Below you'll find the publisher's own description, a quick spec sheet, and a short buyer-beware checklist so you know exactly what you're installing before tapping download.

Install Checklist

Only download through the button on this page — never from third-party mirrors or shortened links, which are the most common way malware spreads.
File size is a light 52.18 MB, so it installs quickly even on modest connections.
This build is signed by "F-Droid Open Source" — always verify the developer name matches what's listed on the app's official store page before installing an update.
After install, Android may prompt you to allow "Install from unknown sources" — approve only this one install, then revoke the permission in Settings > Apps > Special access.
We link directly to the APK file or the publisher's repository; we do not modify the binary. Always run a virus scan after any sideloaded install.

About this app

Use cases:

- Attest the state of a Linux computer

When your computer is in a trustworthy state, you can generate a private key hidden in the TPM2 of your computer. This private key can be sealed with the current state of the computer (PCRs). Then the computer can only sign a message with this key when it is in the correct state according to the PCRs. For example, you can seal the key against the secure boot state (PCR7). If your computer is booting an operating system signed by another vendor, the TPM2 cannot unseal the private key. So if your computer can generate a correct signature, it is in this known state. You can create a sealed private key and create such a signature with cryptographic-id-rs (https://gitlab.com/cryptographic_id/cryptographic-id-rs). This is similar to tpm2-totp (https://github.com/tpm2-software/tpm2-totp) but uses asymmetric cryptography. This means you do not need to keep the verification code secure. You can share it safely with the world.

- Verify the identity of a phone

You can generate a private key when your phone is in a trustworthy state. If your phone can create a correct signature, you know it is the same phone. Since the operating system can access the private key, the security guarantees are much weaker than with a TPM2. So the verification is just as secure as your phone. If you use Graphene OS, also have a look at Auditor (https://attestation.app/tutorial).

- Verify that a person is in possession of a private key

This works as well as the section above but has the same shortcomings. It can be used to verify someone in person when he sends his public key to you in advance over a secure channel.

Details

Version	v0.5
Size	52.18 MB
Developer	F-Droid Open Source
Category	Security
Package	io.gitlab.cryptographic_id
Android	4.1+
Last Updated	Oct 30, 2026
Downloads	6

Frequently Asked Questions

Is Cryptographic ID free to download?
Yes. The APK file linked from this page is free. The developer may offer in-app purchases once installed, but obtaining the installer itself costs nothing.

What Android version does Cryptographic ID require?
Android 4.1+ or newer. Installing on older devices may cause crashes or refuse to install.

Is Cryptographic ID safe to install?
We link to the exact APK published by F-Droid Open Source. We do not modify the file. Still, as with any sideloaded app, scan it with a reputable antivirus before opening it, and only grant permissions the app genuinely needs.

How do I update Cryptographic ID?
Install the newer version on top of the old one — Android will keep your data. If the signature differs, uninstall first (you may lose local progress).

Why is the app not installing?
Common causes: not enough storage, an older Android version than 4.1+, or a conflicting build already installed. Free up space, check your OS version, and uninstall any previous copy before retrying.

How to Download & Install Cryptographic ID

Tap the Download APK button above and save the file to your device.
Open your device Settings → Security (or Apps → Special access → Install unknown apps) and allow your file manager or browser to install unknown apps for this one file only.
Open the downloaded io.gitlab.cryptographic_id.apk file from your Downloads folder.
Tap Install and wait for Android to finish.
Open «Cryptographic ID» by F-Droid Open Source and grant only the permissions it actually needs.
Revoke the "unknown sources" permission once you are done installing.

Note: this page hosts or links to the installer only. The application name, icon and description are provided for identification. All trademarks belong to their respective owners.