<p>With the widespread adoption of distributed networks and cloud storage technologies in the healthcare sector, eHealthcare has garnered significant attention. Leveraging distributed networks, eHealthcare enables patients to access medical services from hospitals across different regions. Cloud storage technology effectively reduces the computational and storage burdens on Healthcare Centers (HCs). However, the use of third-party cloud servers may potentially lead to data privacy breaches. To achieve both privacy protection and fine-grained access control, Multi-Authority Attribute-Based Encryption (MA-ABE) has become widely favored. Nevertheless, existing MA-ABE algorithms produce lengthy ciphertexts, resulting in prolonged encryption and decryption times. This significantly increases the computational load on patients and severely impacts data transmission efficiency. To address these challenges, we propose a decentralized Key-Policy MA-ABE scheme. Our algorithm eliminates the need for a central authority while generating shorter ciphertexts compared to existing MA-ABE solutions, thereby substantially improving encryption and decryption efficiency. Experimental validation using the Java Pairing-Based Cryptography library confirms the performance advantages of our proposed scheme.</p>