Tze Jin WongLee Feng KooFatin Hana NaningPang Hung YiuAhmad Fadly Nurullah RasedeeMohamad Maulana MagimanMohammad Hasan Abdul Sathar2024-05-282024-05-28202021/12/20201857-8365https://doi.org/10.37418/amsj.9.12.72https://research-publication.com/wp-content/uploads/2020/vol-9-n12/AMSJ-2020-N12-72.pdfhttps://oarep.usim.edu.my/handle/123456789/5403Volume :9 No:12The security of LUC type cryptosystems was investigated. In this study, chosen message attack was employed to analyze the security of LUC, LUC3 and LUC4,6 cryptosystems. The cryptanalyst invades the system by obtaining a signature without the sender’s consent, and use it to break the system. Finding shows that LUC4,6 cryptosystem is more resilient against chosen message attack compare with LUC and LUC3 cryptosystems.en-USciphertext, decryption, encryption, keys, Lucas sequence, plaintext.Article1088310894912