A multi-layer optical barcode with security features is described herein. An example method includes illuminating a first phosphor layer on a substrate with light having a first wavelength, wherein the first phosphor layer has luminescent properties such that when it is illuminated by light having the first wavelength, it emits light having a second wavelength, the first phosphor layer is divided into a first two-dimensional grid of cells arranged in a first spatial pattern, wherein each cell of the first phosphor layer corresponds to one bit of an identification code, a first portion of the first phosphor layer is removed from a first number of cells of the first two-dimensional grid of cells to expose the substrate for the first number of cells, capturing a first image of the light emitted by the first phosphor layer having the second wavelength, determining whether the first phosphor layer is authentic based on the first image, and determining the identification code based on the first image.