Ayatollah Boroujerdi University - Department of Electrical Engineering.
In this paper, we use the feature of fingerprint biometric signals to generate random cryptographic keys. The most important feature of this method is the use of unique fingerprint features in the production of random keys. The privacy of the randomly generated biometric key and the complexity of the key generation algorithm are key aspects of key security. In the proposed method, first the unique fingerprint features, which include Minosia dots, are extracted from the fingerprint image. Then, to increase the statistical properties and complexity, the Euclidean distance of all the points of Minosia relative to each other is calculated and stored in a matrix. In the next step, the data of this matrix is moved to 8-bit numbers by permutation operation after normalization. Then, to increase the level of security and the ability to be random, the non-linear operation of the 8-bit S-box used in the AES format password is used. 8-bit data is applied to the S-box separately and the result is stored. Finally, data from low-byte to high-value bytes in 128-bit or 192-bit or 256-bit categories can be used as keys in cryptographic systems. Statistical analyzes performed on the generated keys show the acceptable randomness of the keys. Therefore, the proposed structure for generating a random key can be used in encrypting digital signals with large volumes of data such as image and sound.