Skip to content

Derandom

F-Droid

Open source

Pseudo random number predictor

Version
2.7
Size
3 MB
Updated
Jul 14, 2026
Get from Download APK (v2.7)
Signing certificate on record

About this app

Predicts pseudo random numbers based on a sequence of observed numbers.

Enter a sequence of numbers that you obtained from a pseudo random number generator like, for instance, the Java standard pseudo random number generator or the Mersenne Twister MT19937. The app will then try to predict following numbers from the generator.

The app expects all numbers to be entered as integers or floating point numbers between zero and one. Currently, floating point numbers are supported for the Mersenne Twister only. Three input modes are supported: 1. Text field lets you enter the numbers directly on the device. 2. File lets you choose a file with newline separated number strings. 3. Socket opens a server socket on the device. You can then connect with a custom client by means of a client socket and send newline separated number strings to the server. After each number the server will send back the next newline separated predictions. Each block of predictions is separated by an additional newline.

To test the app, enter the following numbers in the Text field:

1412437139 1552322984 168467398 1111755060 -928874005

These numbers were sampled from the Java linear congruential generator Random.nextInt(). Thus, the app should detect LCG: Java after the third number input, and numbers in the prediction history should appear in green instead of red, indicating that those numbers were correctly predicted.

The source code of this app is published on GitLab. There you can also find a Python program for testing socket input: https://gitlab.com/asnelt/derandom/blob/HEAD/README.md

Licensed under Apache-2.0, by Arno Onken.

OfficialSignature VerifiedOpen Source

What's New in v2.7

Imported from the F-Droid repository index.

  • Made adjustments for Android 17.

Version history

v2.7Latest
Signature continuous

Jul 14, 2026 · 3 MB · Android API 2137 · code 17

Imported from the F-Droid repository index.

  • Made adjustments for Android 17.
INTERNETACCESS_LOCAL_NETWORK

SHA-256 e06fe1efbee5c64195ff69f72cc62456795d51e40517f9c0da4127edd61f5122

v2.6
Signature continuous

Dec 1, 2025 · 3 MB · Android API 2136 · code 16

Imported from the F-Droid repository index.

  • Made adjustments for Android 16.
INTERNET

SHA-256 7a68e55b2e7da4dc7d7b10d1b2208617161b7e0d58680c2d8f20bdfd325f8085

v2.5
Signature continuous

Jul 19, 2024 · 3 MB · Android API 2135 · code 15

Imported from the F-Droid repository index.

  • Made adjustments for Android 15.
  • Improved number history scrolling.
  • Improved reliability of double numbers processing.
  • Updated logo.
INTERNETorg.asnelt.derandom.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION

SHA-256 b92260322efc1ab9741cf1de17b7c56cda1c94f26175997c92c11e406584c492

Will it run on your device?

CompatibilityLikely to run

78%

  • Runs on a broad range of modern Android versions.
  • ABI coverage is focused on newer 64-bit devices.
  • Aligned with the latest Android target SDK expectations.
What changed in this release
Size delta
0 MB
Added permissions
ACCESS_LOCAL_NETWORK
Removed permissions
None

Installation Guide

1

Open Settings on your Android device

2

Go to Security → Unknown sources (or Install unknown apps)

3

Enable "Allow from this source" for your browser or file manager

4

Open the downloaded APK file from your Downloads folder

5

Tap "Install" and wait for installation to complete

6

Launch the app from your home screen

Make sure to re-enable Unknown Sources restrictions after installation for security.

How to install this safely

How to verify the file you downloaded

Before you install anything, confirm the file is the one described here. On a computer, run shasum -a 256 your-download.apk (macOS or Linux) or certutil -hashfile your-download.apk SHA256 (Windows), then compare the output character-for-character with the SHA-256 on this page. If a single character differs, the file is not the build we recorded — delete it.

What the signing certificate proves

Every Android app is signed with a private key that only its developer holds. The fingerprint on this page is a hash of the matching public certificate, and it proves continuity rather than identity: it tells you a build came from whoever signed the earlier ones. Android enforces this at install time — if a package claiming to be org.asnelt.derandom is signed with a different key, the system will refuse to install it over your existing copy. A fingerprint that changes between releases is worth pausing on, because a repackaged app that has been modified by someone else cannot keep the original signature.

How to roll back to an earlier version

If the current release misbehaves, 2.6 is the last build before it. Android will not install an older version code over a newer one, so you must uninstall Derandom first — which clears its local data unless you have a backup. Reinstall the older APK only if its signing fingerprint matches the build you already trust, and check the API range: an older release may target an Android version your device has moved past.

Why we list sources instead of hosting everything

The official store channel is almost always the right choice: it updates automatically and carries the publisher's own distribution guarantees. A direct APK is useful when a device has no store access, when a rollout has not reached your region, or when you need a specific version — and only when the publisher has authorized that copy. APKBrowse does not list pirated, cracked, or unauthorized rebuilds of Derandom, and a listing is removed when the evidence for it stops holding up.

Get Derandom

Every source we list for org.asnelt.derandom is legality-reviewed. Pirated or cracked builds are never offered.

Other sources

F-Droid listing

official

F-Droid builds this app from source and signs it. This is its official listing, with older builds and full release notes.

Source code

verified publisher

The upstream repository this build is compiled from.

We check legality and signature continuity, but device behaviour still varies. Install at your own discretion.

App Information

Developer
F-Droid
Category
Security Privacy
Android
5.0+
Architectures
Version
2.7 (code 17)
Size
3 MB
Updated
Jul 14, 2026
Package name
org.asnelt.derandom

Security Verification

File integrity
SHA-256 recorded
Signing certificate
Fingerprint on record
Official source
Download APK (v2.7)

We record provenance; we do not run malware scans. Verify the hash yourself before installing.

SHA-256 Hash

e06fe1efbee5c64195ff69f72cc62456795d51e40517f9c0da4127edd61f5122

Signing certificate

1dfcde78bf44cd8b6f1a4eb71c216f0141a61a1dbe92dbae2270399a346faf90

Permissions Required

INTERNET
ACCESS_LOCAL_NETWORK

Previous Versions

Signature verified

The signing certificate fingerprint for this release is on record, so a build that does not match it did not come from this publisher.

Report a problem with this listing

A listing is only as good as its corrections. If a source is broken, a signature looks wrong, or this app should not be here, tell the moderation team.

Report a problem