Leakage of exam papers and confidential documents has compromised the security and fairness of the institution as lately highlighted in several incidents. Existing methods using single-point decryption for encryption are prone to misappropriation and system failures whenever the keys are inaccessible. The approach for this is to design a new threshold-based encryption mechanism using (t, n) threshold ECDSA with t < n for the sake of improved security and flexibility in recovering the keys. This scheme introduces a lightweight masking mechanism, reducing computational complexity from \(O\left( {t^{2} } \right) \) to constant-time operations, thereby significantly improving efficiency and scalability. Unlike traditional polynomial-based protocols, the proposed approach ensures robust protection against static corruption by malicious adversaries in the standard adversary model. It allows recovery by any t participants, hence ensuring flexibility and eliminating reliance on a single party. Experimental results reveal that the scheme has high performance improvements with a total operation time of 14.48 ms. Key generation, encryption, decryption, and verification times are significantly reduced, making the scheme practical for real-world applications. The approach combines high security with minimal computational overhead, thus addressing the need for efficient and reliable protection of sensitive documents, such as exam papers. This work delivers an efficient and scalable solution against paper leaks and maintains the integrity and fairness of sensitive processes. The protocol suggested here is quite flexible and efficient with regard to use in applications requiring strong guarantees of security.