Not Getting Strong Even With Keybox: An In-Depth Analysis and Resolution Guide

We understand the frustration that arises when investing time into configuring a robust root environment, only to find that integrity checks and detection systems still flag your device. The scenario described—utilizing a specific keybox, such as the one referenced by the user “yuris 35th keybox,” yet failing to achieve a “strong” integrity status—is a common but complex issue within the Android modification community. We have analyzed the underlying mechanics of Android integrity, Play Integrity API responses, and the interaction between Magisk modules and system environments to provide a comprehensive solution.

This guide is designed to dissect every potential failure point in your setup. We will move beyond basic troubleshooting and explore the technical nuances of how Google’s Play Integrity API, specifically the MEETS_DEVICE_INTEGRITY and MEETS_BASIC_INTEGRITY verdicts, interact with modified boot images. Our objective is to equip you with the knowledge to diagnose why your keybox is not yielding the expected strong integrity results and how to rectify the underlying causes.

Understanding the Core Problem: Integrity Verdicts and Keyboxes

To effectively resolve the issue of “not getting strong,” we must first define what “strong” actually means in the context of modern Android rooting. Prior to late 2023, the SafetyNet API was the primary gatekeeper. However, Google has migrated entirely to the Play Integrity API. This transition changed how devices are evaluated.

The Shift from SafetyNet to Play Integrity

The Play Integrity API assesses your application’s execution environment. It returns three distinct verdicts:

1. MEETS_BASIC_INTEGRITY: Indicates that your device is likely safe from generic software exploits.
2. MEETS_DEVICE_INTEGRITY: Confirms that the device is running an unmodified, genuine Android build.
3. MEETS_STRONG_INTEGRITY: Represents the highest level of assurance, typically requiring a verified boot chain and an untampered hardware-backed keystore.

When users report “not getting strong,” they are usually seeing a DEVICE_INTEGRITY pass but a failure in STRONG_INTEGRITY. Alternatively, they might be receiving a complete failure on all counts. The “keybox” is a set of cryptographic certificates and keys used to sign the device’s attestation statements. If the keybox is detected as compromised, revoked, or mismatched with the device’s reported hardware properties, the attestation fails.

Why a Keybox Might Fail

A keybox is essentially a digital identity card for your device. It must be:

• Valid: Not expired or revoked by the manufacturer (Google).
• Matching: The certificates in the keybox must align with the device’s reported hardware characteristics (model, brand, bootloader status).
• Properly Injected: The system must be able to access and utilize the keybox for signing integrity checks.

If any of these conditions are not met, the Play Integrity API will downgrade the verdict or fail it entirely.

Diagnosing the “Yuris 35th Keybox” Issue

The specific mention of “yuris 35th keybox” suggests the use of a shared or community-sourced keybox. These resources are invaluable, but they come with inherent risks and complexities. We must scrutinize the compatibility between this keybox and your specific device environment.

Device Compatibility and ROM Matching

One of the most common reasons for keybox failure is a mismatch between the keybox source and the target device’s ROM signature. Keyboxes are often extracted from specific devices (e.g., a Pixel 8 Pro on a specific firmware version). If you inject a keybox derived from a Pixel device into a Samsung or Xiaomi device, the Play Integrity API may detect the discrepancy.

• Fingerprint Mismatch: The keybox is tied to a specific “fingerprint” (a hash of the device’s software and hardware). If your device reports a different fingerprint than the one the keybox was signed for, the attestation fails.
• Hardware Attestation: Modern Play Integrity checks query hardware-level features. If the keybox claims to belong to a device with specific hardware (e.g., a Titan M2 security chip) but your device reports different hardware capabilities, the check fails.

Revocation and Usage Limits

Keyboxes are a finite resource. Google actively monitors attestation requests.

• Revocation: If a specific keybox has been flagged as compromised (often due to overuse in public tools), Google will add it to a revocation list. Using a revoked keybox results in an immediate failure.
• Rate Limiting: If a keybox is used on too many unique devices or IMEIs, it triggers rate limits. This often results in a “temporary” failure that can persist for days.

The Role of Magisk and System Modifications

Even with a valid keybox, the underlying system state can block a strong integrity pass. We must ensure that the root environment is as clean as possible, as the Play Integrity API is sensitive to even the slightest system alterations.

Boot Image Patching and Magisk Versions

The method of rooting plays a crucial role.

• Magisk Delta vs. Official Magisk: Some users prefer Magisk Delta for its hiding capabilities, while others use the official build. Ensure your boot image is patched correctly. An improperly signed boot image can trigger boot loader flags that the Play Integrity API detects immediately.
• Zygisk and DenyList: Zygisk is a framework that allows modules to inject code into the Zygote process. While powerful, it can leave traces. We must verify that the Zygisk context is properly configured within the Magisk DenyList (now often called the “Hide Magisk” or “Configure DenyList” section).

The Impact of Magisk Modules

Your screenshots indicate you are using several Magisk modules. This is often the primary culprit for integrity failures. The Play Integrity API scans for known modification patterns.

• Module Interference: Certain modules modify system properties, build props, or the framework itself. These changes can be detected as “tampering.”
• Universal SafetyNet Fix: While historically essential, this module (or its derivatives) can sometimes interfere with the newer Play Integrity API if not configured correctly or if it conflicts with the keybox injection method.
• Systemless Hosts: If you are using a module for ad blocking (like AdAway) that utilizes the systemless hosts module, it modifies the hosts file. While this usually affects basic integrity, aggressive scanning might flag it.
• Busybox and SQLite: Modules that update system binaries (Busybox) or databases (SQLite) can alter file hashes, potentially causing a mismatch with the expected system state.

Comprehensive Troubleshooting Steps

To regain “strong” integrity, we recommend a systematic approach. Do not rush this process; precision is key.

Step 1: The Clean Slate Approach

Before applying complex fixes, we must establish a baseline.

1. Boot to Safe Mode: Temporarily disable all Magisk modules by holding the volume down key during boot (if supported) or using the Magisk app to disable modules individually.
2. Remove Conflicting Modules: Uninstall any modules known to cause integrity issues, such as older SafetyNet fix variants, Riru, LSPosed (unless strictly necessary), and any module that modifies the build.prop directly.
3. Clear Play Services Data: Go to Settings > Apps > Google Play Services > Storage > Clear Data. This forces the Play Integrity API to generate a fresh attestation request.

Step 2: Keybox Injection and Verification

If you are using a pre-packaged keybox or a script to inject it, you must ensure it is applied correctly.

• Injection Method: We recommend using a dedicated module or script designed for the specific keybox format (e.g., a .pem and .pk8 file combination).
• File Permissions: Ensure the keybox files are located in the correct directory (often /data/adb/modules/ within a specific module folder) and have the correct permissions (usually 644 or 600).
• Validation: If you have access to a terminal (Termux), you can attempt to parse the keybox to ensure it is not corrupted. However, without a direct verification tool, the most reliable method is to observe the Play Integrity API response via a tool like the “Play Integrity API Checker” app.

Step 3: Hiding Magisk and Root

The Magisk app itself must be hidden.

• Rename Magisk App: In the Magisk settings, rename the app to something innocuous. This prevents apps from detecting the package name com.topjohnwu.magisk.
• Enforce DenyList: Ensure the “Enforce DenyList” toggle is active. Check the system apps (Google Play Services, Google Play Store, and any banking/game apps) within the DenyList configuration.
• Zygisk Configuration: If your Magisk version supports Zygisk, enable it. However, be aware that Zygisk can be detected by newer integrity checks. Some users find that disabling Zygisk and using Riru-based modules (if available for their Android version) yields better results, though this is version-dependent.

Step 4: Tackling Device Integrity and Fingerprints

If the keybox is valid but the device fingerprint is causing issues, we may need to adjust system properties.

• Custom Build Props: Some modules inject a “safetynet-friendly” build fingerprint. Ensure the fingerprint you are injecting matches the keybox source. If you are using a Pixel keybox, you must ensure your device reports a Pixel fingerprint.
• Warning: Modifying build.prop directly is risky. It is safer to use a systemless module (like “MagiskHide Props Config”) to set these properties dynamically.

Advanced Techniques for “Strong” Integrity

When standard methods fail, advanced techniques are required to bypass the hardware-backed attestation checks.

Hardware Attestation Bypasses

Google’s “Strong Integrity” is designed to be hardware-backed. On newer devices (Pixel 6+, Samsung S22+, etc.), bypassing this is exceptionally difficult because the keys are stored in a secure element (like the Titan M2) that cannot be extracted or spoofed easily.

• The “Unlocked Bootloader” Flag: The primary blocker for Strong Integrity is an unlocked bootloader. If your bootloader is unlocked, Google’s attestation will detect this at the hardware level.
• Workarounds: For devices where hardware attestation is enforced, a true “Strong” integrity pass is often impossible without re-locking the bootloader (which usually requires a fully stock, unrooted ROM). However, for many use cases, achieving MEETS_DEVICE_INTEGRITY is sufficient to pass app checks. If you absolutely require MEETS_STRONG_INTEGRITY, you may need to target older device profiles or specific firmware versions where the hardware check is less aggressive.

Managing Play Integrity API Errors

When checking your integrity verdicts, you may encounter specific error codes.

• Error 8: Integrity API Error: This is a generic error. It often means the API request failed to send or process. Check your internet connection and ensure your Google Play Services are up to date.
• Error 9: nonce generation failed: This indicates an issue with the random string generation used for the attestation request. This is usually a client-side app bug.
• Error 15: Nonce mismatch: The server received a different nonce than what was generated. This can happen if the device clock is out of sync or if the app is manipulated.
• Error 20: Play Store version incompatible: Ensure you are using the latest version of the Google Play Store.

Specific Module Recommendations and Warnings

Based on the context of your setup, we have analyzed the typical module landscape.

Modules to Scrutinize

• Universal SafetyNet Fix: While useful for basic integrity, this module modifies the gms (Google Mobile Services) configuration. If you are using a keybox, this module may be redundant or conflicting. We suggest testing with this module disabled.
• Systemless Hosts Module: If you use ad blockers, keep this module enabled. It generally does not interfere with integrity checks unless it modifies other system files.
• LSPosed / Riru: If you have Xposed framework installed, it significantly alters the system. Most integrity checks will fail with Xposed active. You may need to uninstall Xposed modules to achieve a pass.
• MagiskHide / Shamiko: Shamiko is a popular module for hiding root that works alongside Magisk’s DenyList. Ensure Shamiko is configured correctly. If you are using Shamiko, ensure Zygisk is enabled.

The Importance of Module Order

The loading order of Magisk modules matters. Modules are loaded alphabetically. If you have a module that modifies build.prop and another that modifies the system partition, the interaction between them can cause instability. We recommend keeping your module list minimal.

Troubleshooting the “Keybox” Specifically

Since your issue is centered on the “yuris 35th keybox,” let’s focus on that specific component.

Verifying Keybox Integrity

A keybox consists of two main components:

1. Device Certificate Chain: A series of certificates linking the device to the manufacturer.
2. Private Key: The secret key used to sign the attestation data.

If the private key is public (as is often the case with shared keyboxes), it may be revoked. To test this:

1. Apply the keybox.
2. Reboot.
3. Immediately run a Play Integrity check.
4. If the result is DEVICE_INTEGRITY but not STRONG, the keybox is likely valid but your bootloader state is blocking the strong check.
5. If the result is a complete fail, the keybox is likely invalid or revoked.

Replacing the Keybox

If the current keybox is failing, you must source a new one. When looking for a new keybox:

• Check the Date: Look for keyboxes generated recently.
• Check the Device Source: Look for keyboxes from devices similar to yours (in terms of Android version and security patch level).
• Apply Carefully: Overwriting the existing keybox requires a clean removal of the previous injection method. Ensure no conflicting files remain in /data/adb/.

Final Checklist for “Strong” Integrity

We recommend following this checklist systematically to maximize your chances of success.

1. Clean Environment

• Remove all non-essential Magisk modules.
• Disable Zygisk (Test both Enabled and Disabled states).
• Enable Enforce DenyList.
• Hide the Magisk app.

2. Keybox Application

• Ensure the keybox files are valid and not corrupted.
• Place keybox in the correct module directory.
• Reboot immediately after application.

3. Google Services

• Clear Google Play Services and Google Play Store data.
• Update Google Play Services to the latest version.
• Ensure device time/date are accurate and auto-synced.

4. System Properties

• Verify ro.debuggable is set to 0.
• Verify ro.secure is set to 1.
• Ensure your device fingerprint matches the keybox origin if spoofing.

5. Verification

• Use a reliable checker app (e.g., YASNAC - Yet Another SafetyNet Attestation Checker or a dedicated Play Integrity API checker).
• Look for MEETS_DEVICE_INTEGRITY as a minimum baseline.
• If MEETS_STRONG_INTEGRITY is missing, check your bootloader status. If unlocked, this is expected behavior on newer devices.

Conclusion

The issue of “not getting strong even with keybox” is rarely due to a single factor. It is usually a combination of an incompatible keybox, interfering Magisk modules, and the device’s bootloader state. By methodically isolating variables—testing with a clean module environment, verifying the validity of the “yuris 35th keybox,” and ensuring proper hiding of the root environment—we can narrow down the failure point.

We must emphasize that “Strong Integrity” is increasingly difficult to achieve on modern devices with unlocked bootloaders due to hardware-backed attestation. Focus on achieving MEETS_DEVICE_INTEGRITY first, as this satisfies the requirements for the vast majority of applications. If your specific use case strictly requires Strong Integrity, you may need to investigate specific firmware downgrades or hardware-specific exploits, which are beyond the scope of standard Magisk configurations. Stay diligent, test each change one at a time, and monitor your integrity verdicts closely.