Google has detailed a list of minimum requirements for manufacturers hoping to attach fingerprint sensors to its android operating system.The tech giant, which earlier this month launched a series of Nexus phones featuring fingerprint sensors, wants to put strict guidelines in place to ensure security of biometric data.This seems particularly important given previous negative reports on android's biometric security.The rules for implementing fingerprint sensors are:If a device implementation includes a fingerprint sensor and has a corresponding API for third-party developers, it:MUST declare support for the android.hardware.fingerprint feature.MUST fully implement the corresponding API as described in the Android SDK documentation [Resources, 95] .MUST have a false acceptance rate not higher than 0.002%.Is STRONGLY RECOMMENDED to have a false rejection rate not higher than 10%, and a latency from when the fingerprint sensor is touched until the screen is unlocked below 1 second, for 1 enrolled finger.MUST rate limit attempts for at least 30 seconds after 5 false trials for fingerprint verification.MUST have a hardware-backed keystore implementation, and perform the fingerprint matching in a Trusted Execution Environment (TEE) or on a chip with a secure channel to the TEE.MUST have all identifiable fingerprint data encrypted and cryptographically authenticated such that they cannot be acquired, read or altered outside of the Trusted Execution Environment (TEE) as documented in the implementation guidelines on the Android Open Source Project site [Resources, 96] .MUST prevent adding a fingerprint without first establishing a chain of trust by having the user confirm existing or add a new device credential (PIN/pattern/password) using the TEE as implemented in the Android Open Source project.MUST NOT enable 3rd-party applications to distinguish between individual fingerprints.MUST honor the DevicePolicyManager. KEYGUARD_DISABLE_FINGERPRINT flag.MUST, when upgraded from a version earlier than Android 6.0, have the fingerprint data securely migrated to meet the above requirements or removed.SHOULD use the Android Fingerprint icon provided in the Android Open Source Project.Device makers have to follow these requirements to ensure fingerprint sensors work with Marshmallow and any apps that use its APIs.