Biometry with challenge response pair mechanism

Abstract

Methods for the encoding an encryption key for secure storage are disclosed. The methods rely on the use of unclonable, one-way functions, such as images of biological objects that may be measured according to challenges to result in responses. A biometric print of a biological object is measured with a set of n challenges resulting in n responses. The responses are an ordered sequence, with each response having a fixed position in the sequence. A key is generated of bit length n. A subset of m responses in the full set of n responses is selected, where the selected responses correspond to positions of is in the key. The response subset is stored. The key is then used, and deleted. A party wishing to re-generate the key generates the same set of challenges, measures the same biological object with the challenges a second time, and generates a second set of n responses. Responses in the stored subset of m responses will match responses in the second set of n responses at certain positions in second set of n responses. These matching positions correspond to 1s in the key. The non-matching positions correspond to 0s. Thus, comparison between the response sets recovers the key.