As data volume and complexity increase, conventional software‐based encryption methods face significant challenges, including vulnerability to attacks and high computational demands. This study proposes a hardware‐based cryptographic engine using a dual‐polarity memristive crossbar array with Ta/HfO2/RuO2 memristors, utilizing stochastic and deterministic operations for enhanced security and efficiency. The system integrates random key generation and XOR‐based logic operations within the memristive array, enabling robust encryption and decryption of binary data with a fully resistive data representation. Experimental validation of alphabet image data encryption and the array scale simulation of individual fingerprint authentication are conducted to validate the robustness of the proposed hardware and cryptographic method. The results demonstrate the potential of the proposed hardware for homomorphic encryption, enabling secure data processing without decryption, which can pave the way for memristive hardware to evolve into resistance‐based digital computing hardware.