Ibnu Rusydi; Mukhamad Rizky Akbar; Bagus Januar; Alfin Gimnastiar; Ghufron Makmun Lbs; Mansalwa Utama Nasution; Fathul Hady Raya. THEORETICAL STUDY OF CRYPTOGRAPHY AS A FOUNDATION FOR DIGITAL INFORMATION SECURITY. IJGAM 2026, 2 (1), 414-422.