PENERAPAN ALGORITMA KRIPTOGRAFI KUNCI SIMETRIS DENGAN MODIFIKASI VIGENERE CIPHER DALAM APLIKASI KRIPTOGRAFI TEKS

Abstract

Vigenere Cipher was one of the toughsymmetric-key cryptography algorithm. SinceKasiski been discovered, this algorithm has beenso vulnerable to be deciphered, especially if thecipher text is quite long. Basically the algorithmworks on by yielding some subsequences of text,where the number of the subsequences is equal to the length of the key. And thus, on thismodification each subsequence is encrypted by symmetric-key cryptography algorithms, thatmay differ from each other, and using the samekey. Because the algorithms could be so much,therefore the algorithms used need to be manifested into a file which contains theconfiguration of them, such that this file willlater be one of the key used to open decrypt thecipher text. Since the symmetric key alreadyoccupied,andin orderto enhancethecomplication, the file must be secured using themechanism of public-key cryptography. On thisresearch, the modification of the Vigenere Cipheris implemented in the form of an application thatenable user to do encrpt and decrypt a text withthe concept of the Abstract Vigenere. Thealgorithm may be available only if the algorithmhas been installed and validated by the testcasesregistered in the database.