Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Chemistry

Content Description

1 online resource (xviii, 66 pages) : illustrations (chiefly color)

Dissertation/Thesis Chair

Jan Halamek

Committee Members

Jeremy Feldblyum, Maksim Royzen, Jia Sheng


bioaffinity-based assay, biometrics, biosensor, cipher, Cryptography, encryption, Data encryption (Computer science), Biochemical markers, Colorimetric analysis

Subject Categories

Analytical Chemistry | Biochemistry | Chemistry


Cryptography is a vital component of digital communication and digital data in general. The use of cryptography is necessary to support the veracity of data and to protect it from outside parties with malicious intent. Cryptography focuses on two main facets that are vital for this goal: data encryption and user authentication. Encryption protects the data by transforming it into an encrypted text that would not allow someone access without having or breaking the encryption method that was used to make it. User authentication is a multiple part process that allows for one to be able to identify oneself to prove they were the actual sender of a message. As the processes used for encryption have developed throughout the years, cryptologists have mainly focused on employing the use of ciphers, a character-by-character transformation of data, for high security encryption. For ciphers to work, one requires to possess the encryption key for encryption and a corresponding decryption key for decryption. The work presented in this dissertation focuses on the derivation of these keys through multiple biochemical and chemical methodologies combined with multiple types of cryptographical cipher systems. The requirements for a key through this process are that it needs to be reproducible, but also variable for subsequent keys. For general message encryption, both the encryption and decryption keys are the exact same, as a symmetrical-key cipher system, which requires the results of the experiments performed to be reproducible. Since both the sender and the receiver will be performing the same experiment, the reproducibility of the results is paramount. For these ciphers, a rule is that you do not want to use a key more than once for any subsequent message and to use novel keys for the highest level of security as it is easier to break the cipher if a key is used multiple times1–3. To this end, it is important that the key derivation methodology is variable for subsequent experiments to produce novel keys each time by changing the chosen parameters. Currently, the procedure used for the derivation of keys involves a random number generators (RNGs) or the message sender’s own parameters. However, there are many issues with random number generators with encryption and with their function in general4–7. The research here presents a worthwhile alternative to these RNGs by utilizing biochemical and chemical methodologies as the source for cryptographic keys. In this research, one chemical method is presented in addition to three biochemical methods for various cryptographic ciphers. The biochemical methods involve bioaffinity-based assays with colorimetric responses to produce a signal. The chemical method relies on electrochemical methods to produce data. Three of the methods presented in this dissertation utilize symmetrical-key ciphers, which purely focus on data encryption. For these, a basic addition/subtraction-based cipher is used for the first, and all subsequent experimentation relies on the cipher used as the current standard for encryption today. The final method relies on the use of biomarkers in sweat to produce keys for asymmetrical-key cryptography, which can perform both data encryption and user authentication functions.