Coalescence and Secondary Ice Development in Cumulus Congestus Clouds

Understanding ice development in Cumulus Congestus (CuCg) clouds, which are ubiquitous globally, is critical for improving our knowledge of cloud physics, cloud resolution and climate prediction models. Results presented here are representative of data collected in 1,008 penetrations of moderate to strong updrafts in CuCg clouds by five research aircraft in six geographic locations. The results show that CuCg with warm (> ∼20°C) cloud base temperatures, such as in tropical marine environments, experience a strong collision-coalescence process. Development of coalescence is also correlated with drop effective radius > ∼12 to 14 µm in diameter. Increasing the cloud-base drop concentration with diameters from 15 to 35 µm and decreasing the drop concentration < 15 µm appears to enhance coalescence. While the boundary-layer aerosol population is not a determinate factor in development of coalescence in tropical marine environments, its impact on coalescence is not yet fully determined. Some supercooled large drops generated via coalescence fracture when freezing, producing a secondary ice process (SIP) with production of copious small ice particles that naturally seed the cloud. The SIP produces an avalanche effect, freezing the majority of supercooled liquid water before fresh updrafts reach the −16°C level. Conversely, CuCg with cloud base temperatures ≤ ∼8°C develop significant concentrations of ice particles at colder temperatures, so that small supercooled water drops are lofted to higher elevations before freezing. Recirculation of ice in downdrafts at the edges of updrafts appears to be the primary mechanism for development of precipitation in CuCg with colder cloud base temperatures.

Pengamanan Data melalui Model Super Enkripsi Autokey Cipher dan Transposisi Kolom

One of the essential instruments in the cyber era is data. Therefore, maintaining data security is an important thing to do. One way that can be done to maintain data security is through cryptography. In cryptography, two basic techniques are commonly used, namely substitution techniques and transposition techniques. One of the weaknesses of the basic cryptographic techniques is the lower level of data security. This study proposed a super encryption model in securing data by combining cryptographic algorithms with substitution techniques, i.e., autokey cipher and transposition, i.e., columnar transposition cipher. This study used the Avalanche Effect method as a measurement tool for the proposed super encryption model. The test results have shown that the proposed super encryption model can provide a better level of security. The avalanche effect test on the five data test shows that the average AE value of the proposed super encryption model is 30.76%. This value is higher than the single autokey cipher algorithm of 1.66% and column transposition with a value of 18.03%. Other results from the five data test have shown that the proposed model has a high level of accuracy of 100% in terms of the decryption process results, which is the same as the initial data before going through the encryption process.

A Dynamic Light-Weight Symmetric Encryption Algorithm for Secure Data Transmission via BLE Beacons

Pervasive sensing with Body Sensor Networks (BSNs) is a promising technology for continuous health monitoring. Since the sensor nodes are resource-limited, on-node processing and advertisement of digested information via BLE beacon is a promising technique that can enable a node gateway to communicate with more sensor nodes and extend the sensor node’s lifetime before requiring recharging. This study proposes a Dynamic Light-weight Symmetric (DLS) encryption algorithm designed and developed to address the challenges in data protection and real-time secure data transmission via message advertisement. The algorithm uses a unique temporal encryption key to encrypt each transmitting packet with a simple function such as XOR. With small additional overhead on computational resources, DLS can significantly enhance security over existing baseline encryption algorithms. To evaluate its performance, the algorithm was utilized on beacon data encryption over advertising channels. The experiments demonstrated the use of the DLS encryption algorithm on top of various light-weight symmetric encryption algorithms (i.e., TEA, XTEA, PRESENT) and a MD5 hash function. The experimental results show that DLS can achieve acceptable results for avalanche effect, key sensitivity, and randomness in ciphertexts with a marginal increase in the resource usage. The proposed DLS encryption algorithm is suitable for implementation at the application layer, is light and energy efficient, reduces/removes the need for secret key exchange between sensor nodes and the server, is applicable to dynamic message size, and also protects against attacks such as known plaintext attack, brute-force attack, replaying attack, and differential attack.

A File Encoding Using A Combination of Advanced Encryption Standard, Cipher Block Chaining and Stream Cipher In Telkom Region 4 Semarang

The increase in significant advances in information technology greatly provides comfort and convenience in managing data. This convenience is what makes people who are not responsible for using it as a crime such as hacking, cracking, phishing, and so on. In Telkom Region 4 Semarang, there is a container where there are important company data such as customer data. Customer data is very important and the contents of the data must be kept confidential. The company has experienced significant losses due to information leakage due to negligence in the last 5 years. For this reason, data security is necessary so that data is safe and is not misused. This study applies the Advance Encryption Standard algorithm - Cipher Block Chaining (AES-CBC) and Stream cipher in order to secure data so as to reduce the risk of data theft by telecom subscribers. Based on the average avalanche effect value of AES-CBC and a stream cipher of 49.34%, this shows that the AES-CBC and Stream Cipher encrypted files are difficult to crack so that data confidentiality is well maintained.

Development of a hash algorithm based on cellular automata and chaos theory

Information security, reliability of data transfer are today an important component of the globalization of information technology. Therefore, the proposed work is devoted to highlighting the results of the design and development of a hacking-resistant algorithm to ensure the integrity of information transfer via digital technology and computer engineering. To solve such problems, cryptographic hashing functions are used. In particular, elements of deterministic Chaos were introduced into the developed cyclic hashing algorithm. The investigation analyzes in detail the strengths and weaknesses of known hashing algorithms. They are shown to have disadvantages. The main ones are a large number of matches (Hamming (x, y) and the presence of a weak avalanche effect, which lead to a significant decrease in the reliability of the algorithm for hacking. The designed hashing algorithm uses an iterative Merkley-Damgard structure, augmented by the input message to a length multiple of 512 bits. Processing in blocks of 128-bit uses cellular automata with mixed rules of 30, 105 and 90, 150 and takes into account the dependence of the generation of the initial vector on the incoming message. This allows half of the 10,000 pairs of arbitrary messages to have an inverse Hamming distance of 0 to 2. The proposed algorithm is four times slower than the well-known family of "secure hash algorithms." However, computation speed is not a critical requirement for a hash function. Decreasing the sensitivity to the avalanche effect allows the generation time to be approximately halved. Optimization of the algorithm, as well as its testing was carried out using new technologies of the Java programming language (version 15). Suggestions and recommendations for improving this approach to data hashing are given also

Research on the Cooperation Behavior of Chinese SMEs from the Perspective of Suppliers

The COVID-19 disease has caused great damage to global economy, and the global economic downturn has brought challenges to all aspects of business operations.(International Labour Organisation [ILO], 2020) The business risk of enterprises has increased significantly, and the problem managers currently facing has changed from "how to develop faster" to "how to survive " (Bvuma & Marnewick, 2020). In this context, many peer companies in the supply chain have chosen the strategy of diluting competition and enhancing cooperation, hoping to avoid risks by grouping together. It is true that an effective cooperation model can reduce transaction costs between enterprises, improve information utilization, and enhance enterprises' ability to resist risks. However, some scholars also pointed out that cooperation based on purely economic interests is highly vulnerable. A simple cooperation may not necessarily benefit the enterprise, and it may even deteriorate into "Avalanche effect" (Rui et al., 2010). Keywords: Risk Perception; Trust between Organizations; Decision Preference; Cooperation Behavior.

Extended of TEA: A 256 bits block cipher algorithm for image encryption

<p>This paper introduces an effective image encryption approach that merges a chaotic map and polynomial with a block cipher. According to this scheme, there are three levels of encryption. In the first level, pixel positions of the image are scuffled into blocks randomly based on a chaotic map. In the second level, the polynomials are constructed by taking N unused pixels from the permuted blocks as polynomial coefficients. Finally, the third level a proposed secret-key block cipher called extended of tiny encryption algorithm (ETEA) is used. The proposed ETEA algorithm increased the block size from 64-bit to 256-bit by using F-function in type three Feistel network design. The key schedule generation is very straightforward through admixture the entire major subjects in the identical manner for every round. The proposed ETEA algorithm is word-oriented, where wholly internal operations are executed on words of 32 bits. So, it is possible to efficiently implement the proposed algorithm on smart cards. The results of the experimental demonstration that the proposed encryption algorithm for all methods are efficient and have high security features through statistical analysis using histograms, correlation, entropy, randomness tests, and the avalanche effect.</p>

Energy Efficient Crypto Suit for Secure Underwater Sensor Communication using Genetic Algorithm

With the advancement in technology, there has been a keen interest of researchers and industrial institution in the use of Underwater Sensors Networks (UWSN). This study is devoted to the secure communication between the underwater sensors networks which is now a day’s most widely used for oceanographic abnormalities, and to track submarines that perform the surveillance and navigation. But UWSNs has its limitations such as multipath, propagation delay, low bandwidth, and limited battery as compared to traditional WSNs that causes a low life in comparison with WSNs. Secure communication in UWSNs is more difficult due to the above-mentioned limitations which need ultralightweight components. There are many miscellaneous attacks due to which sensors can be able to lose both data availability and integrity that is why this study is basically to design an efficient algorithm that possesses less computation and use less space for secure communication. The proposed algorithm will initially establish the first half of the key through a genetic algorithm and then will develop the remaining part. After that encryption algorithm is proposed for the secure communication between UWSNs and its performance will be evaluated based on throughput, running time, space usage, and avalanche effect.

Security Analysis of Image Scrambling Cipher Based on Compound Chaotic Equation

As digital image has become one of the most important forms of expression in multimedia information, the security of digital image has become a concern. Because of its large amount of data and high redundancy, there are many security hidden dangers in ordinary image encryption methods. Aiming at the problems of low flexibility and poor anti-interference of traditional image scrambling technology, this paper proposes to select the scrambling diffusion encryption structure in the process of chaotic digital image encryption, which can produce relatively better encryption performance than single scrambling and diffusion scrambling. The composite chaotic operation used in this paper masks the distribution characteristics of chaotic subsequences. Based on the composite chaotic mapping model, the image scrambling password under the two-dimensional chaotic equation is established by scrambling the image in space and frequency domain. Several rounds of experiments show that the algorithm has a large scrambling scheme, further expands the key space of Arnold algorithm, and effectively resists the common computer brute force attack cracking and image decryption cracking methods such as exhaustive, differential attack and known plaintext attack. The improved encryption algorithm can realize the key avalanche effect, is very sensitive to the initial key and has high key security performance, and solves the security problem in the process of image transmission. Several performance syntheses show that the algorithm has high security performance and is suitable for image encryption scheme.