Security in Smart Cities: A Brief Review of Digital Forensic Schemes for Biometric Data

•Smart Cities have a network of interconnected IoT devices that access, store and transmit personal information.•Biometrics, based on face, fingerprint, iris or speech, is used to impart security to user-device interaction.•We enumerate methods that can undermine the integrity of digital image and audio biometric data.•We survey digital forensic schemes that can be used to enhance integrity and privacy of biometric data.