In order to satisfy the requirements of information encryption security in the information era, this paper presents a method of information encryption based on laser-induced breakdown spectroscopy (LIBS) technology. The information to be encrypted was written on white paper with an aqueous solution prepared from zinc gluconate tablets and deionized water. By analyzing the LIBS spectra of white paper and of white paper coated with aqueous zinc gluconate solution, the spectral lines of Zn I at 328.23 nm, 472.22 nm, and 481.05 nm were used to decrypt the information. The LIBS spectra of different positions on the white paper containing the encrypted information were obtained by scanning, and the contrast of the spatial distribution of spectral intensity was improved by baseline correction, normalization, and spectral superposition, allowing the encrypted information to be interpreted more clearly and completely. The experimental results show that this method achieves efficient extraction of hidden information with zinc gluconate tablets commonly used in daily life, and has the advantages of high security, low cost, and convenient production. It provides a new idea for LIBS in the field of information encryption, and has value for certain potential applications.