A Cancelable Multi-Modal Biometric Based Encryption Scheme for Medical Images

In this paper, a novel multi-modal biometric based encryption scheme for medical images is proposed. It is based upon the ever-secure Advanced Encryption Standard Cipher Block Chaining (AES-CBC) mode of encryption and Indexing-First One (IFO) hashing for the generation of the secret keys. The proposed system utilizes two biometrics of the user, the iris and the fingerprint, but instead of using the features of the biometrics directly, they are hashed through the IFO process to create a secret key that can be revoked and regenerated in case of a compromise ensuring the security of the users biometrics. The IFO hashes obtained from the biometric feature vectors are then used as two different secret keys in a two round AES-CBC system to encrypt the medical image. The medical image can be decrypted by performing the AES-CBC rounds in reverse with the correct keys, meaning that with high probability, only the correct user will be able to decrypt the image. This encryption technique improves upon many existing medical encryption schemes based on biometrics, which do not take the protection of the biometric template into account. We were able to perform one full key generation, encryption and decryption in.027 seconds. In addition, this processes is lossless, meaning that there is no change in the pixels of the medical image during the encryption or decryption process, which is necessary of a medical image encryption system.