Molecular Encryption and Steganography Using Mixtures of Simultaneously Sequenced, Sequence-Defined Oligourethanes

Abstract

Molecular encoding in abiotic sequence-defined polymers (SDPs) has recently emerged as a versatile platform for information and data storage. However, the storage capacity of these sequence-defined polymers remains underwhelming compared to that of the information storing biopolymer DNA. In an effort to increase their information storage capacity, herein we describe the synthesis and simultaneous sequencing of eight sequence-defined 10-mer oligourethanes. Importantly, we demonstrate the use of different isotope labels, such as halogen tags, as a tool to deconvolute the complex sequence information found within a heterogeneous mixture of at least 96 unique molecules, with as little as four micromoles of total material. In doing so, relatively high-capacity data storage was achieved: 256 bits in this example, the most information stored in a single sample of abiotic SDPs without the use of long strands. Within the sequence information, a 256-bit cipher key was stored and retrieved. The key was used to encrypt and decrypt a plain text document containing The Wonderf ul Wizard of Oz. To validate this platform as a medium of molecular steganography and cryptography, the cipher key was hidden in the ink of a personal letter, mailed to a third party, extracted, sequenced, and deciphered successfully in the first try, thereby revealing the encrypted document.

Using precision polymer chemistry for plastics traceability and governance

“…70 Molecular data encryption and stenography has also been demonstrated using a multitude of sequence-defined oligourethanes, containing both isotope labelling and halogen (isotopic) tags to assist deconvolution of complex mixtures of sequences. 71 This approach enabled a relatively high amount -256 bits using hexadecimal codeof information to be stored in chemical form and was thus used as an encryption tool which can be deciphered by a third party. To the best of our knowledge, it represents the most amount of information to date stored in a single sample of abiotic sequence-defined polymers.…”

Isotope Ratio Encoding of Sequence-Defined Oligomers

“…For example, one bead-one compound (OBOC) chemical libraries − developed in the context of pharmaceutical research can be deconvoluted by labeling each bead with a chemical tag such as an oligonucleotide or an α-peptide, whose synthesis and analysis can be carried out with high fidelity (Figure A). DNA tags may also be directly covalently attached to the molecule they encode, for example, in DNA-encoded libraries that exploit the fact that DNA can be amplified by PCR. − Alongside, interest has risen in polymer chemistry for sequence-defined polymers which can also be used as tags or simply store information. − Thus, considerable efforts are being devoted to the production of synthetic sequences beyond those of α-peptides and nucleotides, which may be resistant to more drastic conditions than biopolymers, and that may nevertheless be decoded through sequencing methods, primarily by mass spectrometric fragmentation and tandem analysis. − Mixtures of molecules, , including mixtures of peptides or sequence-defined polymers , have recently been proposed for efficient data storage and readout. In some cases, a simple mass spectrum allows for information decoding.…”

“…However, this was before extremely sensitive and accurate mass spectrometers became routine laboratory instruments and before the development of statistical and ranking tools for analyzing MS fingerprints . In a recent publication, Anslyn and co-workers also used isotope ratio encoding to label eight different sequences so that sequence information could be retrieved by iterative depolymerization and subsequent liquid chromatography–mass spectrometry analysis of the products even though the sequences were mixed . Those isotope ratios needed to be easy to read as their role was to distinguish all depolymerized intermediates of each sequence.…”

“…17−19 Thus, considerable efforts are being devoted to the production of synthetic sequences beyond those of α-peptides and nucleotides, which may be resistant to more drastic conditions than biopolymers, and that may nevertheless be decoded through sequencing methods, primarily by mass spectrometric fragmentation and tandem analysis. 20−24 Mixtures of molecules, 25,26 including mixtures of peptides 27 or sequence-defined polymers 22,28 have recently been proposed for efficient data storage and readout. In some cases, a simple mass spectrum allows for information decoding.…”

“…30 In a recent publication, Anslyn and co-workers also used isotope ratio encoding to label eight different sequences so that sequence information could be retrieved by iterative depolymerization and subsequent liquid chromatography−mass spectrometry analysis of the products even though the sequences were mixed. 28 Those isotope ratios needed to be easy to read as their role was to distinguish all depolymerized intermediates of each sequence. To the best of our knowledge, the concept was not implemented further to encode substantial amounts of information, such as the nature of the sequence itself, by mass fingerprints.…”