Abstract: Methods for the storage and retrieval of a digital file are disclosed. The file is encrypted with a random binary key. A mathematical CRP mechanism is used to generate an ordered list of responses from a list of challenges. A subset of responses within the ordered list of responses is selected, which each selected response occupying a position in the ordered list that is the same position as a first binary symbol in the random key. In this way, the key can be encoded in the selection of responses. To recover the key, the selected responses are compared to a full list of responses to determine which of the responses in the full list match selected responses. Matches indicate the first binary symbol in the corresponding position in the key and non-matches indicate the second binary symbol. In this way, the key is reconstructed, and file may be decrypted.

Abstract: Methods for the generation and use of session keys for authentication of a user of a server device are disclosed. The methods use a biological objects of the user to generate responses to challenges. During enrollment, the server device receives a password, hashes it a first number of times, and sends the hash to the user. The user interprets the hash as a set of challenges for the biological object, applies the challenges, and stores the responses. During authentication, the server hashes the password a second number of times, less than the first number, and sends the hash to the user. The user iteratively applies second hash to the biological object, compares the responses to the stored responses, and if there is not a match, hashes the challenges again until there is a match. The number of hashes needed for a match is a session key or subkey.

Abstract: The use of pre-formed arrays of memristors such as ReRAMs for true random number generation is disclosed. The method exploits the natural randomness in the large stochastic cell-to-cell variations in resistance values at low injected current in the pre-formed range. This novel TRNG scheme can be designed with three interconnected blocks: i) a pseudo-random number generator (PRNG) that is acting as an extended output function (XOF) to generate a stream of addresses pointing randomly at the array of ReRAM cells; ii) a method to read the resistance values of these cells at low injected current and convert the values in a stream of random bits; and, if needed, iii) methods to further enhance the randomness of this stream such as, but not limited to, mathematical, Boolean, and cryptographic algorithms.