Biblio

The use of digital images is increasingly widespread currently. There is a need for security in digital photos. Cryptography is a technique that can be applied to secure data. In addition to safety, data integrity also needs to be considered to anticipate the image being manipulated. The hash function is a technique that can be used to determine data authentication. In this study, the Rail Fence Cipher and Myszkowski algorithms were used for the encryption and decryption of digital images, as the Secure Hash Algorithm (SHA-256) algorithm. Rail Fence Cipher Algorithm is a transposition algorithm that is quite simple but still vulnerable. It is combined with the Myszkowski Algorithm, which has a high level of complexity with a simple key. Secure Hash Algorithm (SHA-256) is a hash function that accepts an input limit of fewer than 2∧64 bits and produces a fixed hash value of 256 bits. The tested images vary based on image resolution and can be encrypted and decrypted well, with an average MSE value of 4171.16 and an average PSNR value of 11.96 dB. The hash value created is also unique. Keywords—Cryptography, Hash Function, Rail Fence Cipher, Myszkowski, SHA-256, Digital image.

A hash is a fixed-length output of some data that has been through a one-way function that cannot be reversed, called the hashing algorithm. Hashing algorithms are used to store secure information, such as passwords. They are stored as hashes after they have been through a hashing algorithm. Also, hashing algorithms are used to insure the checksum of certain data over the internet. This paper discusses how Ibn Omar's hashing algorithm will provide higher security for data than other hash functions used nowadays. Ibn Omar's hashing algorithm in produces an output of 1024 bits, four times as SHA256 and twice as SHA512. Ibn Omar's hashing algorithm reduces the vulnerability of a hash collision due to its size. Also, it would require enormous computational power to find a collision. There are eight salts per input. This hashing algorithm aims to provide high privacy and security for users.

The rapid development of technology, makes it easier for everyone to exchange information and knowledge. Exchange information via the internet is threatened with security. Security issues, especially the issue of the confidentiality of information content and its authenticity, are vital things that must protect. Peculiarly for agencies that often hold activities that provide certificates in digital form to participants. Digital certificates are digital files conventionally used as proof of participation or a sign of appreciation owned by someone. We need a security technology for certificates as a source of information known as cryptography. This study aims to validate and authenticate digital certificates with digital signatures using SHA-256, DSA, and 3DES. The use of the SHA-256 hash function is in line with the DSA method and the implementation of 3DES which uses 2 private keys so that the security of digital certificate files can be increased. The pixel changes that appear in the MSE calculation have the lowest value of 7.4510 and the highest value of 165.0561 when the file is manipulated, it answers the security of the proposed method is maintained because the only valid file is the original file.

This article presents a hardware implementation review of a popular family of hash algorithms: Secure Hash Algorithm 2 (SHA2). It presents various schematic solutions and their assessments for 28 nm CMOS technology. Using this paper we can estimate the expected performance of the hardware hash accelerator based on the IC.