EncryptedSharedPreferences

An updated fork of the AndroidX Crypto library (also known as JetSec) for on-going EncryptedSharedPreferences and EncryptedFile support post-deprecation.

This library is unofficial and is not produced, endorsed, supported, or affiliated with Google or the original JetSec maintainers in any way.

The full source of this fork is released under the Apache License 2.0 and was based on JetSec's 1.1.0-alpha07 code.

Background

In April 2025, the androidx.security:security-crypto library was deprecated at version 1.1.0-alpha07. This deprecation had the knock-on effect of causing a lack of on-going support for popular classes provided by the libraries such as EncryptedSharedPreferences and EncryptedFile.

This library forks both the androidx.security:security-crypto and the androidx.security:security-crypto-ktx libraries to provide continuous updates to core dependencies such as tink to allow existing JetSec users to continue to use the functionality securely.

Should I be using this library?

TL;DR - No, probably not.

The existance of EncryptedSharedPreferences has misled many developers by implying that there's an inherent insecurity with SharedPreferences, which is simply not true.

As of Android 10, file-based encryption is enforced on device and through Android's app sandbox model, an attack-vector in which a SharedPreferences is compromised would be difficult to perform and likely require physical access to a device to do so.

Additionally, using EncryptedSharedPreferences also indirectly encourages developers to ignore security-best practises by storing sensitive data on-device. You should always avoid this whenever possible.

However, there are a small number of valid applications for this library or you may just wish to continue to use it based on your own requirements.

For more information and further reading - see my blog post "Securing the Future: Navigating the Deprecation of Encrypted Shared Preferences" to help determine if this library is right for you.

Usage

Add the following dependency to your module-level build.gradle or build.gradle.kts file:

repositories {
  mavenCentral()
}

dependencies {
  // Java
  implementation("dev.spght:encryptedprefs-core:<latest version>")
  // Kotlin  
  implementation("dev.spght:encryptedprefs-ktx:<latest version>")
}

You can then create an EncryptedSharedPreferences instance via the existing JetSec APIs

Java:

MasterKey masterKey = new MasterKey.Builder(context)
  .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
  .build();

SharedPreferences sharedPreferences = EncryptedSharedPreferences.create(
  context,
  "secret_shared_prefs",
  masterKey,
  EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
  EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
);

// Use the shared preferences and editor as you normally would
SharedPreferences.Editor editor = sharedPreferences.edit();

Kotlin:

val masterKey = MasterKey(context = context)

val sharedPreferences: SharedPreferences = EncryptedSharedPreferences(
  context = context,
  fileName = "secret_shared_prefs",
  masterKey = masterKey,
)

// Use the shared preferences and editor as you normally would
sharedPreferences.edit {
  // etc...
}

JetSec Migration Guide

If your project previously used the official 1.1.x JetSec implementation, it should be possible to migrate to this library without breaking existing functionality via the following actions:

• For Java projects, replace your existing androidx.security:security-crypto dependency with dev.spght:encryptedprefs-core:<latest version>
• For Kotlin projects, replace your existing androidx.security:security-crypto-ktx dependency with dev.spght:encryptedprefs-ktx:<latest version>

Within your code, replace any existing instances (e.g. imports) of androidx.security.crypto with dev.spght.encryptedprefs

Known Issues

• Any encrypted shared preference file(s) or encrypted file(s) should not be backed up with Auto Backup as, when restoring, it is likely the key used to encrypt it will no longer be present and will cause runtime crashes. You should therefore exclude all EncryptedSharedPreference or EncryptedFile from a backup using backup rules.

License

Copyright 2025 (C) Ed Holloway-George • spght.dev

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.