Kombinasi Algoritma Advanced Encryption Standard (AES) Dan Shamir’s Secret Sharing (SSS) Pada Keamanan File Microsoft Word

Abstract

Security vulnerabilities in DOC-format documents remain a significant concern, particularly due to the reliance on single-password protection in several versions of Microsoft Word, which exposes documents to key leakage and unauthorized access. This study proposes an enhanced cryptographic approach by combining the Advanced Encryption Standard (AES) for data confidentiality with Shamir Secret Sharing (SSS) for robust key management and distribution. The encryption process involves applying AES to the document contents, followed by partitioning the encryption key into multiple shares using SSS, enabling access only when a predefined threshold of key shares is provided. The proposed method reduces the risk associated with single-point key failure and enhances access control flexibility. Empirical evaluations demonstrate that AES encryption and decryption scale linearly with file size, with encryption times ranging from 0.0001 s (1 KB) to 0.0036 s (1000 KB), and decryption times from 0.00004 s to 0.0030 s. Meanwhile, key splitting and reconstruction via SSS require less than 0.00001 s for typical AES key lengths (16 64 bytes), making the overhead negligible in practical use cases. This research concludes that the combination of AES and SSS presents a reliable and efficient security scheme for protecting DOC-format documents, outperforming conventional single-password encryption mechanisms both in security and performance.