Biometric systems can be GDPR compliant, but not all are. GDPR requires that biometric data must not be improperly stored or transferred - data must stay secure and only be processed with explicit consent.
Local biometrics (like FaceID) are generally compliant since the data never leaves the device, ensuring privacy. However, there are usability and security issues - such as limited device compatibility and difficulty in recovering data if the device is lost.
Centralized biometrics, on the other hand, are not GDPR compliant in most cases because they store biometric data on cloud servers, which may be located in different countries, posing risks of unauthorized access or data breaches.
Decentralized biometrics can be compliant, but it depends on how data is handled. If sharding is used (splitting the data into parts and storing them across servers), the data can still be reconstructed, violating GDPR.
The only way to guarantee compliance without using local biometrics is cloud-based biometrics that transform biometric data into cryptographic keys. These keys cannot be reverse-engineered as they don’t contain any biometric data by themselves. The key is only useful when paired with the device that created it, ensuring biometric data is protected and compliant with GDPR.