On-the-Fly Parallel Processing IP-Core for Image Blur Detection, Compression, and Chaotic Encryption Based on FPGA

It is well known that avalanche effect errors in received noisy ciphertexts will cause severe error propagation in block-ciphered encryption systems, thus resulting in a large reduction in the achievable throughput. However, little is known about the statistical properties of the underlying error sequences in decrypted plaintexts in block-ciphered systems when channel errors are present. A rigorous study of the statistical properties of the errors in block-ciphered crypto-systems operating in cipher block chaining (CBC) mode is provided. The equivalent channel transition probability is obtained and then used to derive error statistics including both error weight probabilities and gap distributions. The validity of the theoretical analyses is confirmed by the excellent match with results obtained by simulated data encryption standard (DES)-based and advanced encryption standard (AES)-based crypto-systems operating in CBC mode. The error statistics will be valuable in the design and performance evaluation of communication protocols, as well as in error-control schemes for block-ciphered crypto-systems in the presence of erroneous ciphertexts, where errors are intentionally left to enhance security against passive eavesdroppers.

This study implements the Advanced Encryption Standard (AES) algorithm in a web-based image encryption system utilizing an ephemeral key generated by an API. The research is motivated by the increasing threats to digital data security, such as identity theft and information manipulation, as well as the weaknesses of static key usage in AES encryption. The developed system consists of a client-side web application and a RESTful API server. The client side, built with HTML, CSS, and JavaScript, receives image input, requests the API for a key, and performs AES-256 encryption in Cipher Block Chaining (CBC) mode with a unique Initialization Vector (IV). The server side generates a random 256-bit key, stores it temporarily for approximately 30 seconds, and sends the key ID to the client. Testing was conducted on images sized 50 KB, 200 KB, and 1000 KB to measure encryption time. The results show that encryption time increases linearly with image size, with minimal overhead that does not affect performance. The ephemeral key approach enhances security by limiting the opportunity for unauthorized access to the key, while client-side encryption ensures that raw image data is never transmitted to the server. These findings demonstrate that implementing AES with ephemeral keys effectively improves the security of web-based image encryption.

Modern cryptographic systems in cloud and IoT environments must balance strong security with real-time performance, yet existing methods often require trade-offs that sacrifice speed for security or introduce latency through conservative designs. This paper presents RNS-AES-CBC-HMAC, a hybrid framework that integrates Residue Number System (RNS) arithmetic with AES-256 and HMAC-SHA256 to deliver both performance and robust security. Using a balanced modulus set $\{2^n - 1,\, 2^n,\, 2^n + 1\}$ for constant-time, carry-free arithmetic mitigates side-channel risks, while AES-256 in Cipher Block Chaining (CBC) mode ensures confidentiality and HMAC-SHA256 provides message integrity with minimal overhead. Implemented in Python 3.10 with PyCryptodome 3.18.0 and tested on an AMD Ryzen~5~2500U, the framework achieved encryption/decryption latencies of $55$--$593\,\mu\text{s}$ for 4--15 character payloads, representing 99\% improvement over previous RNS-based hybrids. It scales linearly in time and memory $\mathcal{O}(n)$, consumes only $21\,\text{KB}$, and produces ciphertext entropy of $7.999\,\text{bits/byte}$, surpassing NIST SP~800-22 standards. This dual-layer architecture effectively counters both passive and active threats, making it suitable for low-latency IoT edge devices and high-throughput cloud systems, merging theoretical number systems with practical cryptography for real-world deployment.

In this paper, we present an enhanced version of a previously published symmetric block cipher implemented for the encryption of digital images. We introduce an additional step of using Arnold’s cat map prior to encryption to improve its quality. After inspecting the statistical characteristics of the ciphertexts for the electronic codebook (ECB) and cipher block chaining (CBC) modes, we found that with this additional step, our schemes produce high entropy ciphertexts for both regular and monochromatic images. Therefore, the results obtained in this paper show that our schemes are indifferent to the Advanced Encryption Standard (AES) cipher. Moreover, due to an effective parallelization of matrix operations, we think that our proposal can be executed reasonably fast.

The Consultative Committee for Space Data Systems (CCSDS) recommends AES algorithm as a cryptographic algorithm to maintain confidentiality and data security between spacecraft and ground systems. In implementation, there are several AES algorithm operating modes including Cipher-Block Chaining (CBC), Electronic Codebook (EBC), Cipher Feedback (CFB), Output Feedback (OFB), and counter mode (CTR). One of the operating modes of AES algorithm recommended by CCSDS is CTR because it has advantages in terms of efficiency of implementation and offers a high level of data security. LAPAN-A4 as the next generation of LAPAN satellites also uses CCSDS standard in terms of data exchange between satellites and ground stations including telemetry and telecommand (TTC) data and satellite payload data. In order to protect LAPAN-A4 satellite data, especially TTC data, in this paper AES algorithm was implemented in CTR operating mode on the FPGA which will then be implemented on LAPAN-A4 satellite onboard data handling (OBDH) as one of LAPAN-A4 satellite data security systems. To overcome the limited resource of FPGA, optimization is also done using basic iterative AES hardware reused method, which is to reuse hardware that has been designed n times for same operation for AES algorithm. From the results of implementation and optimization, efficiency of logic gates used is increasing almost a quarter less than the previous research.

With the increasing importance of data security in digital image transmission and storage, this research presents an implementation of an image encryption and decryption program using the Advanced Encryption Standard (AES) algorithm combined with Message Authentication Code (MAC) for enhanced security. The program utilizes AES in CipherBlock Chaining (CBC) mode to ensure confidentiality and integrity of the image data. The unique key and initialization vector (IV) enhance the security of the encryption process. Additionally, the inclusion of MAC ensures data integrity and prevents unauthorized modifications during transmission or storage. The program offers a user-friendly web-based interface for easy usability. The implemented solution provides a high level of security for image data and can be applied in various applications requiring secure image transmission and storage. The effectiveness and reliability of the program are demonstrated through experimental results and evaluation.

Chapter 4 - Domain 3: Security Architecture and Engineering

Recently, massive research works have been accomplished for augmenting privacy and security requirements for cybersecurity applications in wireless communication networks. This is attributed to the fact that conventional security processes are not appropriate for robust, efficient, and reliable multimedia streaming over unsecure media. Therefore, this paper presents an efficient color image cryptosystem based on RC6 with different modes of operation. The proposed cryptosystem is composed of two phases: encryption and decryption. The encryption phase starts by decomposing the color plainimage with few details into its RGB components, which in turn, are segmented into 128-bit blocks. These blocks are then enciphered using RC6 with an appropriate mode of operation. After that, the corresponding enciphered blocks of RGB components are multiplexed for constructing the final cipherimage. This scenario is reversed in the decryption phase. The performance of the proposed cryptosystem is gauged via simulation using a set of encryption quality metrics. The simulation results reveal that the proposed cryptosystem with cipher block chaining (CBC), cipher feedback (CFB), and output feedback (OFB) modes can efficiently and effectively hide all information of the color images with few details even in the presence of some input blocks with similar data. On the other hand, the results show that the electronic codebook (ECB) mode is not effective at all in hiding all details of images. Finally, the obtained results ensure the applicability of the proposed cryptosystem and its efficiency in encrypting images in terms of security, encryption quality, and noise immunity.

A novel method for one-way hash function construction based on spatiotemporal chaos

This research presents a technique for concealing messages within images by combining AES encryption in Cipher Block Chaining (CBC) mode with Least Significant Bit (LSB) embedding. A key feature of this method is the dynamic generation of the encryption key based on intrinsic statistical properties of the image—specifically, the standard deviation of the RGB channels—This eliminates the necessity for external key exchange, making the encryption process inherently dependent on the image itself.

Security is one important issue regarding data and information today. Steganography along with cryptography is used to hide and secure information. It is already an established practice to put watermark and to secure a single document using encryption. However, for large information requiring multiple documents has not received any attention. Here a program which can do steganography to multiple PDF documents to increase its steganography capacity is proposed, it is named MPDFStego. One of the steganography technique chosen in this research is the Least Significant Bit (LSB). LSB technique can be applied to Portable Document Format (PDF) by making use of its Tj Operator. Secret text is encrypted using Advanced Encryption Standard with 128-bit key size in Cipher Block Chaining (CBC) mode before it is embedded into the PDF document(s). Recompression and decompression of the PDF document(s) are done outside MPDFStego, with the help of QPDF tool. Testing and evaluation show that the MPDFStego is capable of hiding the secret text into one or many PDF documents (s).

In this paper, the authors analyze the applicability of artificial intelligence algorithms for classifying file encryption methods based on statistical features extracted from the binary content of files. The prepared datasets included both unencrypted files and files encrypted using selected cryptographic algorithms in Electronic Codebook (ECB) and Cipher Block Chaining (CBC) modes. These datasets were further diversified by varying the number of encryption keys and the sample sizes. Feature extraction focused solely on basic statistical parameters, excluding an analysis of file headers, keys, or internal structures. The study evaluated the performance of several models, including Random Forest, Bagging, Support Vector Machine, Naive Bayes, K-Nearest Neighbors, and AdaBoost. Among these, Random Forest and Bagging achieved the highest accuracy and demonstrated the most stable results. The classification performance was notably better in ECB mode, where no random initialization vector was used. In contrast, the increased randomness of data in CBC mode resulted in lower classification effectiveness, particularly as the number of encryption keys increased. This paper provides a comprehensive analysis of the classifiers’ performance across various encryption configurations and suggests potential directions for further experiments.

Compression purpose to reduce the redundancy data as small as possible and speed up the data transmission process. To solve the size problem in saving data and transmission process, we use Run Length Encoding and Fibonacci Code algorithm to do compression process. Run Length Encoding and Fibonacci Code algorithm is a type of lossless data compression used in this research, which performance will be measured by comparison parameters of the Compression Ratio (CR), Redundancy (RD), Space Saving (SS) and Compression Time. The compression process is only done on image files with Bitmap format (*.bmp) and encode using Run Length Encoding or Fibonacci Code, then perform the compression process. The final result of the compression is file with extension *.rle or *.fib which contains compressed information that can be decompressed back. The output of the decompression result is an original image file that is stored with *.bmp extension. Fibonacci algorithm will give a better compressed size on image color, while in a grayscale image Run Length Encoding will give a better compressed size. Based on the results of research at two different types of images, each algorithm has its own advantages. Fibonacci Code algorithm is better for color image compression while Run-Length algorithm Encoding is better for grayscale image compression.

In this paper, we propose a novel block cipher mode of operation, which is known as the counter chain (CC) mode. The proposed CC mode integrates the cipher block chaining (CBC) block cipher mode of operation with the counter (CTR) mode in a consistent fashion. In the CC mode, the confidentiality and authenticity of data are assured by the CBC mode, while speed is achieved through the CTR mode. The proposed mode of operation overcomes the parallelization deficiency of the CBC mode and the chaining dependency of the counter mode. Experimental results indicate that the proposed CC mode achieves the encryption speed of the CTR mode, which is exceptionally faster than the encryption speed of the CBC mode. Moreover, our proposed CC mode provides better security over the CBC mode. In summary, the proposed CC block cipher mode of operation takes the advantages of both the Counter mode and the CBC mode, while avoiding their shortcomings.

Recently, to enhance the security of the Internet of Things (IoT), research on blockchain-based encryption algorithms has been actively conducted. However, because blockchains have complex structures and process large amounts of data, there are still many difficulties in using the conventional blockchain-based encryption algorithms in an IoT system that must have low power consumption and be ultra-lightweight. In this study, to address these problems (1) we simplified the conventional Directed Acyclic Graph (DAG)-based blockchain structure, and (2) we proposed a new Advanced Encryption Standard (AES)-Cipher Block Chaining (CBC) algorithm with enhanced security by periodically changing the secret key and initialization vector (IV) in the conventional AES-CBC encryption algorithm. Because the DAG, which is the conventional blockchain structure, randomly transmits data to multiple blocks, there may be overlapping blocks, and the quantity of transmitted data is not limited; thus, the time and power consumption for encryption and decryption increase. In this study, a simplified DAG was designed to address these problems so that packets can be transmitted only to three blocks, without overlapping. Finally, to verify the effectiveness of the algorithm proposed in this paper, an IoT system consisting of 10 clients and one server was implemented in hardware, and an experiment was conducted. Through the experiment, it was confirmed that when the proposed AES-CBC algorithm was used, the time taken and the amount of power consumed for encryption and decryption were reduced by about 20% compared to the conventional AES-CBC algorithm.