Cascaded holography coupled with the secret-sharing scheme has recently gained considerable attention due to its enhanced information processing and encryption capabilities. Here, we propose a new holographic iterative algorithm and present the implementation of cascaded liquid crystal (LC) holography for optical encryption. Each LC layer acts as the secret key and can generate a distinct holographic image. By cascading two LC elements, a new holographic image is formed. Additionally, we showcase the dynamic optical encryption achieved by electrically switching LCs with combined electric keys. This work may offer promising applications in optical cryptography, all-optical computing, and data storage.