<p>To ensure the confidentiality and security of shared data and to prevent unauthorized access and theft, a shared data hiding encryption method based on a hyperchaotic system is proposed for local area network (LAN) application scenarios. In the proposed method, the characteristics and attributes of LAN shared data are utilized as inputs to the employed hyperchaotic system. Through this hyperchaotic system, a set of dynamic initial values that match the real-time state parameters of LAN shared information variables can be generated adaptively, and these initial values are determined by the characteristics and attributes of LAN shared data without random selection. Based on these variable values, a digital information key and an image information key for the LAN are generated. Using these two keys, a two-way authentication process based on the hyperchaotic system is designed. In this process, following two-way authentication of the user's registered login password and USB key, the shared information in the LAN is encrypted by combining the digital information key, the image information key, and the SHA-256 hash function algorithm for double hidden encryption. Experimental results show that this method has a key space of 10⁹⁰, which is sufficient to resist brute-force attacks in LAN environments. When encrypting a 256 × 256 image, the number of pixels change rate (NPCR) reaches 99.63%, the unified average changing intensity (UACI) reaches 33.41%, and the ciphertext information entropy reaches 7.98 bits. A single round of hyperchaotic two-way authentication takes only 200 microseconds, and the energy consumption for encrypting 2000&#xa0;MB of data is 15&#xa0;mJ. This demonstrates that this method provides strong encryption for both digital and image-based information hiding in LANs and can effectively perform two-way authentication for legitimate users within the LAN.</p>