Ciphertext-Independent and Unbounded Depth RSA-Based Updatable Encryption Scheme

We introduce a novel updatable encryption scheme based on the RSA cryptosystem to address the challenges of key rotation in secure communication systems. Updatable encryption allows ciphertexts encrypted under an old key to be transformed into ciphertexts under a new key without decrypting the plaintext, thereby enhancing security without compromising data integrity or confidentiality. Our RSA-based scheme leverages the mathematical properties of RSA to enable efficient and seamless key updates. We provide a security analysis demonstrating that our scheme is not vulnerable to information leaking. Experimental results indicate that our method offers a practical and efficient solution for large-scale systems that require regular key updates, with minimal impact on computational resources and performance.