Apparently, there is (or there should be) no way to bypass this protection and decrypt the data unless the correct password is provided. The passcode is required to generate the actual encryption key it will be used instead of the “default_password” for that purpose. This happens before most Android services, let alone the apps, are allowed to start. If, however, the secure startup option is enabled, the phone will ask for the passcode early during the boot process. Notably, even before the user unlocks the display, the data partition is mounted and decrypted the apps are allowed to start and to access their data. Once Android finishes the boot process, the screen will be still locked and must be unlocked with a PIN/pattern/passcode (but not Smart Lock or any biometric sensor, at least if the manufacturer didn’t screw up this part – which many do). If secure startup is not enabled, the encryption key will be automatically generated during the boot sequence based on a combination of a certain hardware-dependent key and the passphrase “default_password” no user input is required. The principal difference between “secure startup” and “no secure startup” lies in how the device produces the decryption key to access information on the data partition. The phone will then prompt the user whether they want the phone to ask for their PIN/pattern/password on startup. If the user changes their mind and wants to activate the “Secure startup” option at a later time, he or she will have to first remove the PIN/pattern/password from the device, and then re-enable protection. This option is called “Secure startup”, and can be configured during the initial setup while specifying the lock screen password. Users not satisfied with the default protection level can opt to encrypt their phones with a much stronger key based on a combination of a hardware key (again) and user input (passcode, pattern etc.) on device startup. In other words, bypassing such encryption can be non-trivial. While this protection scheme is obviously orders of magnitude less secure than full-disk encryption in iOS devices, it still provides reasonable protection to an average consumer. The encryption key is protected with Trusted Execution Environment (TEE), a dedicated part of the CPU that will only execute small pieces of signed code (trustlets).īy default, the actual encryption key that is used to encrypt and decrypt the data is based on a combination of a unique hardware key and the phrase “default_password”. In modern devices featuring 64-bit processors (basically everything from Qualcomm Snapdragon 410 and all the way up to the recent Snapdragon 845), full-disk encryption is software-accelerated with dedicated ARMv8 commands. Starting with version 5.0, Android offers reasonable protection with full-disk encryption (FDE). Many thanks to Oleg Davydov from Oxygen Forensics for his invaluable help and advise.Īndroid Full-Disk Encryption, Secure Startup and File-Based Encryptionīefore we start discussing how manufacturers can bypass encryption, let us first have a look at the types of encryption available in Android. So how do the suppliers of forensic software overcome encryption, and can they actually extract anything from an encrypted Android smartphone locked with an unknown passcode? We did our own research. While this Google’s policy initially caused concerns among the users and OEM’s, today the strategy paid out with the majority of Android handsets being already encrypted. There is no user-accessible option to decrypt the device or to otherwise skip the encryption. Each Google-certified Android device released with Android 6.0 or later must be fully encrypted by the time the user completes the initial setup. On the other side of this coin is encryption. The companies claim to support tens of thousands of models, creating the impression that most (if not all) Android devices can be successfully acquired using one method or another. Numerous vendors advertise many types of solutions for extracting evidence from Android devices.
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