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Kriptografi menjadi salah satu metode data hiding yang cukup populer hingga sekarang. Sejak zaman Yunani kuno, kriptografi sudah marak digunakan untuk penyembunyian suatu pesan teks dan terus berkembang dengan seiringnya waktu hingga saat ini. Salah satu teknik keamanan data dapat dilakukan menggunakan kriptografi dan steganografi. Penggunaan kedua metode ini sudah ramai menjadi perbincangan karna dapat lebih meningkatkan tingkat keamanan dengan sangat signifikat. Metode kriptografi memiliki banyak jenis dan pengguanaannya sangat fleksibel karena terdapat berbagai metode klasik maupun moderen yang dapat menjadi salah satu pilihan penggunaannya dalam berbagai situasi dan permintaan. Berdasarkan penjabaran tersebut dapat diungkapkan bagaimana implementasi metode kriptografi klasik caesar cipher dikombinasikan dengan metode kriptografi moderen DES pada sebuah pesan teks dan akan dilapisi keamananannya kembali dengan cover image menggunakan metode steganografi LSB agar lebih terjamin keamanan privasinya. Kriptografi sebagai salah satu ilmu dalam keamanan informasi, yang digunakan dalam proses pengamanan pesan dan penyisipan dalam gambar citra menggunakan metode steganografi serta pengecekan noise gambar sebelum dan setelah enkripsi menggunakan metode PSNR.

Cryptography is widely used to secure data and information so that it is not easily misused by parties who are not interested in the data. One type of cryptographic algorithm is Caesar Cipher and Vigenere Cipher. Both of these algorithms are classic cryptographic algorithms that need to be modified so that they become more optimal in the data security process. The first modification is to modify the Vigenere key using Fibonacci. In general, Vigenere Cipher will repeat the same keyword to complete the number of characters that are lacking so that the number of characters is the same as the number of characters in the plaintext. The second modification is to change or convert plaintext letters into ASCII letters so that the code is more difficult to solve. After the ASCII conversion process is done, the next results will be converted back in Hexa letters. In addition to the two modifications made, the steganography technique is also added by hiding the code behind the media in the form of images. Images that are sampled will be renamed and stored in different places.

Information data security is an important aspect of exchanging data and information. Data and information security can be done in various ways, including by using the cesarean cipher method in cryptographic techniques. The cesarean cipher method of cryptographic technique is a substitution coding system which is done by replacing each alphabet character with other characters along the 26 alphabet characters so that the coding only occurs in the alphabet itself without any other punctuation. This study proposes a modification to the cesarean cipher technique by adding to the number of characters used, namely 256 characters in the ASCII code. The caesar cipher application or CaesarApp uses the methodology of library study, consultation, application design and application testing. The implementation of the CaesarApp application was created using the open-source Android Studio 3.5 application. The results of tests conducted on the CaesarApp application note that the modification of the caesar cipher with 256 ASCII characters results in a secure information data security application, this application has a deficiency in reading limitations on ASCII characters, so characters cannot be read properly on android users.

Image is an object that has been used by various people since long ago. Utilization of these images evolve in line with advances in technology. Image in this information technology era is not only in a physical form, there is also a form of so-called digital image. Many people use digital images for personal use, so prone to be manipulated by others. Cryptographic technique, such as Caesar Cipher and OTP is a security techniques that can be applied to the digital image to avoid manipulation or theft of data image. The result is, an image can be read only by the sender and the recipient's image alone. Combined the two algorithms have fast turnaround time, up to 0.017791 seconds for the image to the size of 512x341 and 0.032302 seconds for the image to the size of 768x512. In addition, the resulting image has a very low degree of similarity, with the highest PSNR value obtained is 6.8653 dB. It can be concluded that the combined algorithm and OTP Caesar Cipher algorithm is fast and difficult to solve.