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The dissemination of personal data through digital media has increased significantly alongside the growing use of Quick Response (QR) Codes for various purposes, such as electronic tickets, certificates, and digital identities. Conventional QR Codes are open and can be easily scanned, copied, or manipulated by unauthorized parties. The personal data referred to in this study includes sensitive information such as full name, identity number (NIK/National ID), date of birth, address, phone number, and email address. This research proposes a layered security system that combines the Advanced Encryption Standard (AES) cryptographic algorithm with steganography using the Discrete Cosine Transform (DCT) method. The process begins with encrypting personal data using AES, converting the encrypted result into a QR Code, and embedding the QR Code into a digital image using DCT, hiding it in the image’s frequency domain. The digital images used are of fixed size and formats that preserve visual quality. System evaluation is carried out by testing the visual quality of the stego image, the success rate of QR Code extraction, and the integrity of the encrypted data. The results are expected to conceal sensitive information visually while maintaining its confidentiality, with potential applications in electronic ID cards, digital certificates, e-tickets, and other confidential documents.

This research presents the development of a transaction data protection mechanism for a bouquet sales application by utilizing the Advanced Encryption Standard (AES) algorithm. The rapid growth of digital commerce has led to an increase in online transactions, which in turn raises serious concerns regarding the security of sensitive transaction data. Information such as customer identities, order details, delivery addresses, and payment data are vulnerable to unauthorized access, data leakage, and manipulation if not properly secured. To address these issues, this study applies the AES-128 encryption algorithm using a 128-bit secret key to secure transaction data before it is stored in the system database. The encryption process follows the standard AES workflow, including key expansion, initial transformation, multiple encryption rounds, and a final transformation stage. Decryption is restricted exclusively to authorized users who possess the correct encryption key. The research methodology includes system analysis, AES integration into the application, and functional testing of the encryption and decryption processes. Data integrity is validated by comparing the original plaintext with the decrypted output, while system performance is evaluated based on processing time and decryption accuracy. Experimental results indicate that the average encryption and decryption time remains under 10 milliseconds per transaction, without affecting system performance. The findings confirm that AES-128 effectively enhances transaction data confidentiality and integrity in the bouquet sales application

This research aims to develop a transaction data security system on the web-based Pancadaya Waste Bank application by applying a hybrid cryptographic algorithm that combines Advanced Encryption Standard (AES) and Rivest Shamir Adleman (RSA). The problem faced in the previous system is the weak recording and security of customer transaction data, because the process is still carried out manually so that it is prone to recording errors, loss of important information, and potential misuse of data by unauthorized parties. To answer these problems, this study uses the Rapid Application Development (RAD) method which allows the application development process to be carried out quickly, flexibly, structured, and according to user needs. The research method used was a qualitative approach with interview techniques with the management of the Pancadaya Waste Bank and the Environment Office, as well as an in-depth literature study on the application of hybrid cryptographic algorithms in modern information systems. The system is built using the PHP programming language, MySQL database, and OpenSSL library as the main support for the data encryption and decryption process. The implementation of the algorithm is carried out by encrypting transaction data using AES for efficiency and speed, then the AES key is secured through RSA to ensure a higher level of security while preventing illegal access. The test results showed that the system was able to encrypt and decrypt transaction data in real-time, as well as display transaction results in the form of digital notes on deposit and balance withdrawal activities. In addition, performance tests using GTmetrix showed that the application has excellent speed, stability, and processing efficiency, making it feasible to be widely implemented in Pancadaya Waste Bank operations.

This study aims to develop a data security system for the Pancadaya Waste Bank web-based application by implementing a hybrid cryptography algorithm combining AES and RSA. The main problem identified is the vulnerability of manually recorded and unsecured transaction data. The research applied a qualitative approach through interviews with system users and the Environmental Agency, as well as literature reviews on hybrid cryptography algorithms. The system was developed using the Rapid Application Development (RAD) method and implemented using PHP, MySQL, and the OpenSSL library. The results show that the system successfully encrypts transaction data using AES and secures the AES key with RSA, thereby enhancing data security. Testing with GTmetrix indicates excellent application performance. Furthermore, the system can display and decrypt real-time transaction data in receipt form for both deposit and withdrawal processes. This application provides an innovative solution to data management and transaction security issues in digital-based waste bank systems.

The more rapid development of information technology, this has an impact and can cause changes in people's thinking patterns in communicating. In the past, the way people used to communicate remotely was still manual, namely by using letters. The lack of efficiency in sending letters encourages people's mindsets to create innovations that facilitate long-distance communication, namely via SMS, email, WhatsApp and the internet. One of the impacts of the development of message delivery technology is the tapping of data which makes the user feel insecure. One way to secure data breaches is by securing the sender's and recipient's email passwords using AES (Advanced Encryption Standard) cryptography. We conclude that the AES algorithm can be applied to encrypt passwords, so that passwords cannot be easily read by other users. In addition, the password will not be easily cracked.

(Cryptography Advanced Encryption Standard (AES) for File Document Encryption). Advanced Encryption Standard (AES) is a cryptographic algorithms as a standard symmetric key encryption algorithm that used in current time. AES 128 has 1 blok plaintext with 128 bit sized, where in the process of cryptographic algorithms, first the plaintext is converted into hexadecimal-sized 4 x 4 matrices called the state, where each element of state has 1 byte size. The process of encryption on AES is the transformation towards the state repeatedly in the 10th round. Each round of AES requires one key result of the key generation using 2 basic transformation, i.e. substitution and transformation. AES encryption using 4 transformation by the following sequence: subbytes, shiftrows, mixcolumns, and addroundkey. On the other hand, the process of decryption is using the inverse of all the basic transformation of AES algorithm, except addroundkey. Therefore, the sequence of transformation on the decription is invshiftrows, invsubbytes, invmixcolumns, and addroundkey. In the data text, the encryption process is initiated with convertion the data text into ASCII code in hexadecimal numbers that are molded into the matrix 4 x 4 bytes. Next, do some basic transformation such as subbytes, shiftrows, mixcolumns, and addroundkey. However, when performing the transformation, the processed data on every trasformation is in the form of binary data obtained from the hexadecimal matrix. AES 128 bit cryptography have room 2128 keys which is a tremendous value and is considered secure to use to avoid the brute force attack.

In the daily use of technology, humans cannot be separated from the internet as a need to exchange information. People at this time spend more time in front of computer screens, laptops, even smartphones to find out information, send data to some of their friends. One of the information that is often sought or sent is a file. Apart from that, image files are files that are much searched for and sent, and many also contain important information in them. Image file security is of course very important so that unauthorized parties do not hack or manipulate information from the image. There is a way to secure information so that it does not leak to unauthorized parties, namely by using cryptography and steganography. By combining these two methods, you can maintain the confidentiality and security of a file, especially image files. In this study the algorithm and method used is the AES cryptographic algorithm (Advanced Encryption Standard) 256 and the LSB (Least Significant Bit) steganography method. Data integrity needs to be tested to ensure that the encryption and decryption processes are running properly. Data integrity testing uses the SHA-1 method. Likewise, the image quality after insertion will experience a decrease in quality. To evaluate this, it is necessary to test using the PSNR method. From the results of data integrity testing by comparing the hash value of the decrypted image file with the original image file, there is no difference. So this shows that the encryption and decryption process was successful. While in testing using the PSNR method, the average PSNR value is 44.14086 dB and with an average error value of 2.830403 dB, which means there is a small decrease in quality. From the implementation and testing results, it can be concluded that the AES 256 cryptographic algorithm and the steganography method LSB can be implemented in maintaining the confidentiality and security of secret messages.