High‐Security X‐Ray Imaging Encryption Based on Irreversible Acid‐Responsive Radioluminescence Memory Scintillator

Abstract X‐ray imaging encryption has garnered significant attention but remains vulnerable to information leakage and hard to detect breaches. Herein, an irreversible acid‐responsive radioluminescence memory scintillator, Zn _1.3 Ga _1.4 Ge _0.3 O ₄ :Cr ³⁺ @Zn ₂ GeO ₄ :Eu ³⁺ (ZGGO@ZGO), is developed, which not only enhances information security but also enables real‐time leakage detection. The ZGGO@ZGO exhibits visible and near‐infrared (NIR) dual‐emitting persistent radioluminescence (PRL), in which the visual signal acts as a decoy to mislead potential offenders. Upon acid treatment, Zn ₂ GeO ₄ :Eu ³⁺ (ZGO) shell undergoes rapid degradation, enabling ZGGO@ZGO to realize the transformation of dual‐emitting PRL into single‐emitting imperceptible NIR PRL. The transformation of PRL effectively prevents visual detection by the naked eye, allowing decryption only through a charge‐coupled device (CCD) camera to reveal the hidden information. Through engineering a dual‐layer security system composed of ZGGO@ZGO and ZGO, visual misdirection is synergized with sequential logic gates requiring acid treatment and CCD detection, significantly reducing leakage risks. Importantly, the acid‐responsive PRL transformation is irreversible. Once decoded, the information is permanently locked in its altered state, allowing the detection of information leakage and the effective mitigation of subsequent harm. This approach surpasses traditional encryption methods by providing both enhanced security and the ability to identify unauthorized access, potentially revolutionizing information protection in sensitive applications.