Could Photon-DSP be applied to any brightly colored surface?

Yes, a painting by Matisse, Cezanne, Kandinsky, or Han Hofmann or anybody could be illuminated, and the photons sent to sensors, and then arrayed by an Optical Digital Spectrum Analyzer into a peaks profile, and that peaks profile would be linked to the painting.

But, this would NOT be a reliable way to authenticate.

Why?

First the spectral range from 450 nm to 850 nm is very narrow compared to the spectral range of fluorescent light 200 nm to 1500 nm.

Second visible light is visible, not invisible like most fluorescent light. Visible light (the Balmer Series) is a small part of the fluorescent spectral range which also includes the Lyman Series and the Paschen Series).

Third visible light can be produced a low cost, whereas any full wide profile of fluorescent peaks could only be produced at high cost and with much advanced technology and knowledge of chemistry and physics. Many criminals have a few dollars and a small amount of ability. Few criminals have a lot of dollars and a great amount of skill in chemistry and physics.

So, yes Photon-DSP could be applied to a painting by Mondrian, for example, and a profile of peaks could be made. But using visible light from a painting would not be a secure way to authenticate any document, painting, package, or item. You could do it, but don’t do it when lives are at stake or vast sums of money.

Fluorescent Photon-DSP is not absolutely infallible either. The peaks profile could be reverse engineered and faked. But the DSP aspect is strictly a one-time pad. Utterly non formulaic, unpredictable, not algorithmic, not on your smartfone, no on you i-phone, not gonna be deciphered even if you have a quantum computer. Much more secure than 4 rotor Enigma with a plugboard. Or 6 rotor. Or 8 rotor.

I make my own Ln+3 combos. I bake, scinter, anneal, microwave, of electro-static deposit them myself. I use all sorts of molar concentrations, some as low as Ln+3 at 0.02% and some as light as Ln+3 at 40%.

I make all my own snippets. Sometimes a few, sometimes thousands. Some are narrow, some are wide. They can be here, there or anywhere along the 200 nm to 1500 nm spectral range that my astronomy grade sensors can detect.

So, it’s best to use fluorescent light, not light from a painting by Seurat. If you want to be secure, do it my way. Don’t bet innocent human lives and large sums on visible light offshoots of Photon-DSP.