True-Photonic Strategy for Chemically Encrypted Two-Factor Authentication with Unlimited Chemical Passwords Based on Cascade Energy Transfer under a Single Wavelength Excitation

Abstract

Here, we report a simple generalized platform for a molecular password system based on zero- to three-step excitation energy transfer involving four readily available commercial fluorescent dyes, Coumarin 1, Curcumin, Rhodamine 123, and Rhodamine B, under single wavelength excitation at 360 nm in 9:1 (v/v) 1,4-dioxane–acetonitrile. The input keys or password characters are chemically composed and defined by the quaternary concentrations of four individual dyes, and the fluorescent readouts at multiple wavelengths against such unique dye compositions identify each character. These passwords could be encrypted and communicated as sets of quaternary concentration values or sets of points on a principle component analysis (PCA) graph that would be difficult to understand without the identities of the dyes, involved chemical process, and solvent composition. The primary drawback of the reported chemical password systems is the limited number of active passwords that prevents them from real applications. The present molecular password system supports all-active 44 (256) four-character passwords from four chemical inputs and the password length could be increased to generate 45 (1024) five-character, 46 (4096) six-character, 47 (16 384) seven-character, and 48 (65536) eight-character passwords, which have been partially demonstrated. The system retains the scope to increase the password length further. Such a dynamic nature of chemical passwords makes the molecular security system perfect for complex applications like two-factor authentication (2FA) that demands the simultaneous verification of long static passwords as well as short one-time passwords. Chemical passwords, spectroscopic verification, and strong chemical encryption eventually must make the 2FA process most secured. We present here the rationale to design a robust molecular password system as a powerful tool for data processing and information protection through chemical encryption that would work well with another set of molecules too.

pH‐Controlled Transition from Disaggregation to Reaggregation of Bis‐indolyl(phenyl)methane−β‐CD Conjugate Appended with Multi‐logic Operations

“…The present macro‐molecular security system, (BIPM−β‐CD−OH − ), provided the possibilities of functionally mimicking the electronic password systems, however, retaining the intrinsic advantages of chemical password systems. Additionally, as the chemical keys generate distinct ‘optical fingerprints’, the total number of active passwords could be increased with increasing the character length of the passwords as we shown in one of our previous studies [8b] . Increasing the number of password characters from three to four to five and so on would provide 3 3 , 3 4 , 3 5 , etc.…”

“…Use of molecules as signal transducers and photons as signal carriers can provide outstanding benefits for highest level of data protection. Molecules have presented their ability in producing non‐linear changes in between the input and output photonic signals through participating into a variety of photophysical and photochemical processes, hence endow unusual security measures over the electronic systems [8a–c,9] . Already, a good number of chemical security systems were reported, [8,9] however, many of them primarily restricted in repeat‐key‐entry providing fewer active passwords and operational keys [8d–f] .…”

Communicating Supraparticles to Enable Perceptual, Information‐Providing Matter

“…[173] Therefore, an intermixed CSP architecture might be suitable to specifically exploit cascade energy transfer interactions to achieve single wavelength excitation for multiple different luminescent species that would not be simultaneously excitable without their interaction (Figure 5b1). [128,174] A core-shell architecture can be the structural motif of choice if reduced interaction between two different signal carrier types within a CSP is desired. This can be of particular interest for hybrid-encoded CSPs using magnetic and optical signal-carrying building blocks.…”

A Cu 2+ triggered reversible photochromic system: the structure photochromic response relationship study and potential applications

“…In addition, the detail photochromic properties and potential application of the newly developed photochromic system was investigated by using compound g (R 2 , R 4 = Br, R 3 = OH) as the model substrate. The critical advantages of this system such as fast response, good fatigue resistance and moderated thermal bleaching rate made it a promising candidate material for information storage and encryption [30][31][32]. In addition, applications to use this photochromic system in the preparation of photochromic glass, special security ink, molecular logic gate and security information storage device were performed.…”