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This study analyzes the performance of the Dual Modulus RSA algorithm in securing text data using Python. The rapid growth of digital technology has increased the risk of data security threats, making efficient and secure encryption essential. Dual Modulus RSA is a modification of the classic RSA algorithm that uses two different moduli in the encryption and decryption process, thus increasing security levels because attackers must factorize two moduli simultaneously. This research uses an experimental quantitative approach by measuring the execution time of encryption and decryption processes with variations in plaintext length (5, 10, and 15 characters). Implementation was carried out using Python 3 with the time.perf_counter() function for microsecond-precision measurement. The results show that the Dual Modulus RSA algorithm successfully encrypts and decrypts all test plaintexts correctly. Encryption time ranged from 0.0212 ms to 0.0823 ms, while decryption time ranged from 0.0422 ms to 0.0955 ms. There is a positive linear relationship between plaintext length and processing time. Decryption is consistently slower than encryption due to the larger private key exponent (d1=2753, d2=3533) compared to the public exponent (e=17). The main factors affecting performance are exponent size, dual modulus overhead, CPU caching effects, and Python interpretation overhead. This study recommends using Dual Modulus RSA with hybrid encryption for practical implementation to balance security and performance.

Fully Homomorphic Encryption (FHE) enables computation on encrypted data with end-to-end confidentiality; however, its practical adoption remains limited by substantial computational costs, including long encryption and decryption times, high memory consumption, and operational latency. Zero-Knowledge Proofs (ZKPs) complement FHE by enabling correctness verification without revealing sensitive information, although they do not support encrypted computation independently. This study integrates both techniques to enable encrypted computation with verifiably consistent results. A prototype system is implemented in Python using Microsoft SEAL for homomorphic encryption and PySNARK for Zero-Knowledge Proof verification. Experiments are conducted on standard consumer-grade hardware (Intel i5, 8 GB RAM, Ubuntu 22.04) using datasets ranging from 100 MB to 1 GB. The evaluation focuses on encryption and decryption time, homomorphic computation latency, memory usage, and proof generation overhead. Experimental results show that integrating ZKPs introduces a moderate and stable runtime overhead of approximately 15–20%, as analyzed in Section 4, while enabling verification without plaintext disclosure. Ciphertext expansion remains a notable limitation, with observed growth of approximately 30–40× relative to plaintext size, consistent with prior FHE implementations. Despite these overheads, the system demonstrates feasible scalability for datasets up to 1 GB on mid-level hardware. Overall, the results indicate that the integrated FHE+ZKP approach provides a practical balance between confidentiality, verifiability, and performance, supporting its applicability to privacy-preserving scenarios such as secure cloud computation, encrypted data analytics, and confidential data processing under realistic resource constraints.

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

Data security is a critical aspect in the digital era due to the increasing exchange of sensitive information through electronic media. One widely used approach to protect data confidentiality is cryptography, particularly asymmetric encryption algorithms. This study aims to analyze the implementation of the Rivest–Shamir–Adleman (RSA) algorithm as a data security mechanism through an encryption and decryption process. The research method used is an experimental approach by implementing the RSA algorithm in a text-based data security simulation. The stages include key generation, encryption, and decryption processes, followed by analysis of the correctness and effectiveness of the algorithm in maintaining data confidentiality. The results show that the RSA algorithm is capable of converting plaintext into unreadable ciphertext and successfully restoring it to its original form through the decryption process using the correct private key. This confirms that RSA provides a high level of security based on the difficulty of factoring large prime numbers. The implication of this study is that the RSA algorithm can be effectively applied to secure sensitive data transmission in information systems, especially in environments requiring strong authentication and confidentiality.

Information security is an essential aspect of digital communication, particularly in the exchange of text-based messages through open networks. Messages transmitted without protection are vulnerable to interception and unauthorized modification. One classical cryptographic technique that remains relevant as a foundational learning tool is the Caesar Cipher algorithm. This study aims to implement the Caesar Cipher algorithm for message encryption and decryption and to analyze its effectiveness and security level. The research method employed is a descriptive approach through literature review and a case study by applying character-shift techniques to text messages. The results indicate that the Caesar Cipher algorithm successfully transforms plaintext into ciphertext and restores it back to its original form through the decryption process. Although the algorithm is simple and easy to implement, it has significant limitations in terms of security due to its small key space and vulnerability to brute-force attacks. Therefore, Caesar Cipher is not suitable for protecting sensitive data but remains valuable as an introductory model for understanding basic cryptographic concepts.

The exchange of information in the digital era has become a general need for society. However, the information sent often has a public or confidential nature. Therefore, security is needed so that confidential information remains safe. Cryptography is a field of knowledge used to secure information using encryption and decryption processes. One of the cryptographic methods used is the permutation method, which changes the layout, sequence, or structure of data into a form that is difficult to understand without knowledge of the exact key. Implementing cryptography using the permutation method in Android-based applications can increase the security and privacy of user data, as well as protect sensitive information from unauthorized access. This research aims to implement permutation method cryptography in Android-based applications to protect the confidentiality or privacy of user data. By using the permutation method, the sequence of bits or characters in the data is scrambled so that it is difficult for unauthorized parties to understand. The research results show that the implementation of permutation method cryptography in Android applications can provide a higher level of security in maintaining data confidentiality. However, it is worth considering that simple permutation methods may not be secure enough to deal with more sophisticated attacks. Therefore, choosing a stronger cryptographic method needs to be considered to achieve a higher level of security. In conclusion, implementing cryptography using the permutation method in Android-based applications can increase the security and privacy of user data. The permutation method is able to randomize the sequence of bits or characters in the data so that it is difficult for unauthorized parties to understand. However, for a higher level of security, it is necessary to consider stronger cryptographic methods.

MP3 audio files are often used in a variety of fields, but they are prone to security risks such as eavesdropping and illegal access. This study proposes a super encryption method by combining the algorithms of Rivest Shamir Adleman (RSA) and ElGamal to improve the protection of audio data. RSA was chosen for its efficiency and ease of implementation, while ElGamal offers a high level of security through discrete logarithmic complexity. The combination of the two is expected to address the weaknesses of each algorithm and strengthen file security. The system is developed using the Python programming language with the Visual Studio Code environment. The encryption process is done in layers: MP3 files are first encrypted with RSA, and then the results are encrypted again with ElGamal. The decryption is done in reverse order. Tests are conducted with various MP3 file sizes to measure the effectiveness and performance of the system. The results show that this method is able to secure audio files so that they cannot be accessed without the private keys of both algorithms. Although processing times are increased compared to single encryption, the level of security obtained is much higher. This approach can be an effective solution for protecting digital audio data, particularly MP3 format, and could potentially be applied to a wide range of other data types that require a high level of security.

The widespread use of digital images, driven by low-cost, handheld acquisition devices, has increased the need for robust security measures to safeguard privacy. This demand is further underscored by rising identity theft and other image-related crimes. This study presents a chaos-based experimental evaluation of contemporary image encryption algorithms. Owing to intrinsic properties such as sensitivity to initial conditions and pseudo-randomness, chaos theory has become increasingly prominent in image encryption. Five chaos-based image encryption schemes were selected and applied to a dataset of 26 color images. The evaluation covers both encryption performance and cryptographic security. Decryption quality is measured using Mean Squared Error (MSE), Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), and DeepEns. Cryptographic security is assessed using entropy, correlation coefficient, Number of Pixel Change Rate (NPCR), Unified Average Changing Intensity (UACI), average and maximum deviation, and histogram analysis. Experimental results indicate that all evaluated schemes demonstrate strong cryptographic security and comparable encryption performance, with broadly similar effectiveness across methods.

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.

Rapid technological developments have penetrated various aspects of human life, including data and information security. Amidst the threat of data leaks and misuse, information protection has become crucial. One solution to maintain data confidentiality is to implement cryptography technology. Cryptography is the study of techniques to secure messages so they cannot be read by unauthorized parties. This process is carried out by encoding the original message (plain text) into an unreadable form (cipher text), which can only be understood by those who possess the key to decrypt it. This study used the Caesar Cipher algorithm, a form of classical cryptography. This algorithm uses a substitution method, where each letter in the message is shifted by a certain amount based on a predetermined key. Caesar Cipher is a symmetric algorithm, meaning the key used for encryption is also used for decryption. The security of this algorithm lies in the secrecy of the key, which is known only to the sender and recipient of the message. This method is relatively simple, but still relevant for securing data with low to medium sensitivity levels. This study used WhatsApp messages as the object to be encrypted using the Caesar Cipher algorithm. The results show that encrypted messages become unintelligible without prior decryption. This demonstrates that the Caesar Cipher can protect messages from unauthorized parties. Therefore, implementing this algorithm can be an initial solution for maintaining data confidentiality in digital communications, especially on platforms vulnerable to eavesdropping or unauthorized access. Its primary benefit is maintaining message integrity and confidentiality to prevent misuse.  

Advances in technology and computers are utilized in various fields of contemporary applications, especially in cryptography and data security in graph theory applications. By understanding the concepts of graph theory, researchers and developers can design cryptographic algorithms that are stronger, more efficient and resistant to attacks. One of the cryptographic applications that has been implemented is the XNOR algorithm. This algorithm has been applied to encryption and decryption as well as the use of stream ciphers. By using 64 bits, the XNOR algorithm can expand encryption and decryption capabilities and increase the security of encrypted data. In this research, an analysis was carried out regarding information encryption and decryption algorithms with the application and development of the XNOR gate logic circuit method in Boolean algebra and graph theory. This research uses the example of the word MATH, which can be changed into a code or password and vice versa to secure information that you want to keep secret. Apart from that, an analysis of the graph formation of each character in the word MATH was also carried out using Python which produced semi-Euler and Hamilton graphs  

Along with the increasing threat of cybercrime, which is predicted to cause losses of up to US$10.5 trillion by 2025 , penetration testing (pentest) has become a crucial strategy for identifying security vulnerabilities. However, the manual pentest process is often time-consuming. This research aims to analyze the role, effectiveness, and challenges of Generative AI (GenAI), specifically GPT-4.1, in accelerating and optimizing the penetration testing process. This research method uses a qualitative approach with a case study on the "PumpkinFestival" VulnHub machine , where GPT-4.1 is integrated into the Kali Linux environment through the ShellGPT tool. The results show that GPT-4.1 can significantly accelerate all stages of the pentest, from reconnaissance to exploitation. GenAI proved effective in analyzing scan results, composing specific payloads, and creating decryption scripts quickly and accurately , while also filling a research gap by evaluating a newer AI model compared to previous studies. The implication is that the integration of GenAI in cybersecurity has great potential to increase the efficiency and effectiveness of security teams in facing increasingly complex threats.

Along with the development of the times, the use of information technology using computers as its media has increased rapidly. Indonesia is currently starting to adopt the concept of society 5.0 or what is known as Society 5.0, where this kind of activity focuses on community settings that are oriented towards IT-based human activities (Wijayanti et al., 2022). The application of the concept of "society 5.0" has brought many technological advances in various fields of life that are connected to the internet, especially in Indonesia. The base64 technique produces values ​​during text encoding that are difficult for laypeople to understand. This encryption program has the ability to convert plain text to cipher text and reverse cipher text after it is received. Several recommendations for the development of better applications in further research can be made based on the test findings of this study and the conclusions mentioned above. These include the following: The Vigenere Chipper application can only encrypt text messages    

Cryptography (cryptography) is the science and art of keeping messages safe. The sender of the message will encrypt it while the recipient of the message will decrypt it. The encryption and decryption process uses keywords that have been agreed upon by the sender and recipient of the message. To better understand the development of cryptography, this journal will introduce a comparison of classical cryptography and modern cryptography at the level of computer network security. The cryptography that will be compared is Caesar Cipher and AES. This study uses the method of literature review (library research), namely research based on expert opinion and the results of previous studies.    

(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.

The RC-5 algorithm is an algorithm with the encryption method using the symmetric method and processing in the form of a cipher block, the same keywords are used for the encryption and decryption processes. The testing and analysis phase consists of a). Testing the execution time of the key generation process (set up key) b). Testing the success of the encryption and decryption process on the client-server integration method c). Testing the success of the encryption and decryption process using the file operation method d). Comparison of overhead/file size before and after passing through the system. The testing phase and execution time analysis are carried out when using the file operation method where the test will be divided into 3 parts, namely the execution time for the key setup process, the encryption process, and the decryption process. Testing the success of the encryption and decryption process on the client-server integration method is divided into 2 parts, namely testing the encryption process and the decryption process. In testing the encryption process, the characters that will be sent to the server will be encrypted first with a key to becoming a ciphertext in the form of integer data. The test results obtained are 1). The execution time for key generation (set up key) is very fast, around 9-10 ns. 2). In the encryption and decryption process, the execution time depends on the size of the plaintext file. The larger the plaintext file size, the longer the execution time. Where for a file with a size of 1 kb requires an execution time of 50.6 ms in the encryption process. 3). There is no difference between the size of the file before entering encryption and after decryption. Where for files with a size of 500 bytes before entering the encryption process, a file of 500 bytes will be generated from the decryption process.

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.    

In order to send data or information  processed by using cryptography people can use XML(eXtensible Markup Language). XML data are general texts file which consist of several different tagswhich are defined by the XML document maker. In this research, the XML data were processed by usingPassword Based Encryption cryptography. This method consists of encryption and decryption meant toalter plaintext into chipertext which in turn creates chipertext from plaintext by using password key.²The implementation of the program in this research is a prototype of Hospital’s web facilitated withencyption menus and decryption data which are meant to protect the saved data which are in turn accessedand processed by authorized people. The implementation of the program is built as a web application withJava Server Page (JSP) in NetBeans 6.0 with Password Based Encryption cryptography provided by JavaCryptography Extension (JCE).

Cryptography is a science which studying about safety of messages, so it makes themessages cannot be read by unauthorized persons. Cryptography have two kinds of algorithmfirst is encryption algorithm, that is algorithm altering plaintext become the ciphertext, and thesecond is decryption algorithm that is algorithm altering ciphertext become the plaintext,  thatconducive of message can only be made and read by authorized persons. Plaintext represent themessage able to be read,  while ciphertext is message which have pass by the encryption process,so that order the ciphertext difficult to be translated or read. And method of substitution andtranspotition method are some of conventional technique able to be used to protect the picturesfiles, so that produce the pictures files which do not easy to to be read. The conventionaltechnique basically use a same key to do the encryption  and decryption process.