KeyEncoder: A secure and usable EEG-based cryptographic key generation mechanism

Nowadays, a rapid, easy, and convenient access to our private information is essential to carry out both personal and professional activities. In most cases, this information is sensitive and can be stolen due to its importance and the lack of security protocols. In this study we propose a time–invariant cryptographic key generation mechanism based on electroencephalogram (EEG) signals. We employed Discrete Wavelet Transform and autoencoders to extract the biometric features from the EEG signals. Using these features, we construct a scheme to generate secure seeds that can be used as inputs for secure hash functions and obtain cryptographic keys. The mechanism proposed preserves the privacy of the user, as the cryptographic key is generated for each new EEG signal received, avoiding the need of storing the key, previous EEG signals or any other information. Results show that the proposed mechanism is secure against random attacks, as a 0% of False Acceptance Rate is reported, while generating seeds with an entropy of 0.968 in less than 500 ms.