The Auditor app uses hardware security features on supported devices to validate the integrity of the operating system from another Android device. It will verify that the device is running the stock operating system with the bootloader locked and that no tampering with the operating system has occurred. It will also detect downgrades to a previous version. Supported devices:

* BlackBerry Key2 (BBF100-1 and BBF100-6 models)
* BQ Aquaris X2 Pro
* Google Pixel 2
* Google Pixel 2 XL
* Google Pixel 3
* Google Pixel 3 XL
* Google Pixel 3a
* Google Pixel 3a XL
* Huawei Honor 7A Pro (AUM-L29 model)
* Honor 9 Lite (LLD-L31 model)
* Huawei Honor 10 (COL-L29 model)
* Huawei Honor View 10 (BKL-L04 and BKL-L09 models)
* Huawei Mate 10 (ALP-L29 model)
* Huawei Mate 20 lite (SNE-LX1 model)
* Huawei Mate 20 Pro (LYA-L29 model)
* Huawei P smart 2019 (POT-LX3 model)
* Huawei P20 (EML-L09 model)
* Huawei P20 Pro (CLT-L29 model)
* Huawei Y7 2019 (DUB-LX3 model)
* Huawei Y9 2019 (JKM-LX3 model)
* HTC EXODUS 1
* HTC U12+
* LG Stylo 5 (LM-Q720 model)
* LG Q Stylo 4 (LG-Q710AL model)
* Motorola moto g⁷
* Motorola One Vision
* Nokia 3.1
* Nokia 6.1
* Nokia 6.1 Plus
* Nokia 7.1
* Nokia 7 Plus
* OnePlus 6 (A6003 model)
* OnePlus 6T (A6013 model)
* OnePlus 7 Pro (GM1913 model)
* Oppo R15 Pro (CPH1831 model)
* Oppo A7 (CPH1903 model)
* Oppo A5s (CPH1909 model)
* Realme C2 (RMX1941 model)
* Samsung Galaxy A70 (SM-A705FN model)
* Samsung Galaxy Amp Prime 3 (SM-J337AZ model)
* Samsung Galaxy J2 Core (SM-J260A, SM-J260F and SM-J260T1 models)
* Samsung Galaxy J3 2018 (SM-J337A and SM-J337T models)
* Samsung Galaxy J7 (SM-J737T1 model)
* Samsung Galaxy M20 (SM-M205F model)
* Samsung Galaxy Note 9 (SM-N960F and SM-N960U models)
* Samsung Galaxy Note 10 (SM-N970F and SM-N970U models)
* Samsung Galaxy Note 10+ (SM-N975U model)
* Samsung Galaxy S9 (SM-G960F, SM-G960U, SM-G960U1, SM-G960W and SM-G9600 models)
* Samsung Galaxy S9+ (SM-G965F, SM-G965U, SM-G965U1 and SM-G965W models)
* Samsung Galaxy S10e (SM-G970F model)
* Samsung Galaxy S10+ (SM-G975F model)
* Samsung Galaxy Tab A 10.1 (SM-T510 model)
* Samsung Galaxy Tab S4 (SM-T835 model)
* Sony Xperia XA2 (H3113, H3123 and H4113 models)
* Sony Xperia XZ1 / XZ1 Compact (G8341 and G8342 models)
* Sony Xperia XZ1 Compact (G8441 model)
* Sony Xperia XZ2 (H8216 model)
* Sony Xperia XZ2 Compact (H8314 and H8324 models)
* T-Mobile REVVL 2
* Vivo 1807
* Xiaomi Mi A2
* Xiaomi Mi A2 Lite
* Xiaomi Mi 9
* Xiaomi POCOPHONE F1

It cannot be bypassed by modifying or tampering with the operating system (OS) because it receives signed device information from the device's Trusted Execution Environment (TEE) or Hardware Security Module (HSM) including the verified boot state, operating system variant and operating system version. The verification is much more meaningful after the initial pairing as the app primarily relies on Trust On First Use via pinning. It also verifies the identity of the device after the initial verification.

See https://attestation.app/tutorial for detailed usage instructions. This is included as the Help entry in the app menu. The app also provides basic guidance through the process. See https://attestation.app/about for a more detailed overview.

* https://github.com/GrapheneOS/Auditor
* https://github.com/GrapheneOS/AttestationServer
* https://github.com/GrapheneOS/AttestationSamples