2nd International Conference of Computer, Environment, Social Science, Health Science, Agriculture & Technology (ICEST) 2017 5-7 May 2017, Medan, Indonesia

Vigenere Cipher is one of the classic cryptographic algorithms and included into symmetric key cryptography algorithm, where to encryption and decryption process use the same key. Vigenere Cipher has the disadvantage that if key length is not equal to the length of the plaintext, then the key will be repeated until equal to the plaintext length, it course allows cryptanalysts to make the process of cryptanalysis. And weaknesses of the symmetric key cryptographic algorithm is the safety of key distribution factor, if the key is known by others, then the function of cryptography itself become useless. Based on two such weaknesses, in this study, we modify the key on Vigenere Cipher, so when the key length smaller than the length of plaintext entered, the key will be generated by a process, so the next key character will be different from the previous key character. In This study also applied the technique of Three-pass protocol, a technique which message sender does not need to send the key, because each using its own key for the message encryption and decryption process, so the security of a message would be more difficult to solved.

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Classical cryptography is a way of disguising the news done by the people when there was no computer. The goal is to protect information by way of encoding. This paper describes a modification of classical algorithms to make cryptanalis difficult to steal undisclosed messages. There are three types of classical algorithms that are combined affine chiper, Caesar chiper and chiper transposition. Where for chiperteks affine chiper and Caesar chiper can be looped as much as the initial key, because the result can be varied as much as key value, then affine chiper and Caesar chiper in this case is dynamic. Then the results of the affine and Caesar will be combined in the transposition chiper matrix by applying the pattern of rice cultivation path and for chipertext retrieval by finally applying the pattern of rice planting path. And the final digit of the digit shown in the form of binary digits so that 5 characters can be changed to 80 digit bits are scrambled. Thus the cryptanalyst will be more difficult and takes a very long time to hack information that has been kept secret.

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Cryptography is still developing today. Classical cryptography is still in great demand for research and development. Some of them are Vigenere Cipher and One Time Pad (OTP) Algorithm. Vigenere Cipher is known as the alphabet table used to encrypt messages. While OTP is often used because it is still difficult to solve. Currently there are many ways to solve the Vigenere Cipher algorithm. OTP itself has constraints with the distribution of keys that are too long. The key length in the OTP algorithm is the same as the plaintext length. Key random creation also increases the intensity of key distribution. This requires a secure network at a high cost. The key repeater also lowers the message security level. EM2B Key algorithm is able to overcome key problem in OTP. EM2B and Increment of Key (Lk) collaborations produce key lengths equal to plaintext. The Rotation of Matrix (ROM) algorithm contributes to manipulating the length of plaintext characters. ROM works with Square Matrix tables that also scramble the contents of plaintext. The addition of Vigenere Cipher further enhances plaintext security. The algorithm was developed with the EnC1 function, Subrange (Si), and Length of Plaintext (Lp). This research produces a very strong ciphertext. Because plaintext undergoes four stages of encryption to become cipherteks. Then the length of the plaintext changes with the number of cells in the matrix. The value of Si and Lp is added to the plaintext to be a flag for the decryption process.

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The caesar cipher modification will be combine with the transposition cipher, it would be three times encryption on this experiment that is caesar modification at first then the generated ciphertext will be encrypted with transposition, and last, the result from transposition will be encrypted again with the second caesar modification, similarly at the decryption but the process is reversed. In the modification of caesar cipher, what would be done is the shift of letters are not based on the alphabet but based on ASCII table, plaintext will get the addition of characters before encryption and then the new plaintext with the addition of characters will be divided into two, they are plaintext to be encrypted and plaintext are left constantly (no encryption), The third modification is the key that is used dynamically follows the ASCII plaintext value.

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In the first journal, I made this attempt to analyze things that affect the achievement of students in each school of course vary. Because students are one of the goals of achieving the goals of successful educational organizations. The mental influence of students’ emotions and behaviors themselves in relation to learning performance. Fuzzy logic can be used in various fields as well as Clustering for grouping, as in Learning Development analyzes. The process will be performed on students based on the symptoms that exist. In this research will use fuzzy logic and clustering. Fuzzy is an uncertain logic but its excess is capable in the process of language reasoning so that in its design is not required complicated mathematical equations. However Clustering method is K-Means method is method where data analysis is broken down by group k (k = 1,2,3, .. k). To know the optimal number of Performance group. The results of the research is with a questionnaire entered into matlab will produce a value that means in generating the graph. And simplify the school in seeing Student performance in the learning process by using certain criteria. So from the system that obtained the results for a decision-making required by the school.

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One Time Pad (OTP) is a cryptographic algorithm that is quite easy to be implemented. This algorithm works by converting plaintext and key into decimal then converting into binary number and calculating Exclusive-OR logic. In this paper, the authors try to make the comparison of OTP cryptography using KPI and KCT so that the ciphertext will be generated more difficult to be known. In the Key and Plaintext Insertion (KPI) Method, we modify the OTP algorithm by adding the key insertion in the plaintext that has been splitted. Meanwhile in the Key Coloumnar Transposition (KCT) Method, we modify the OTP algorithm by dividing the key into some parts in matrix of rows and coloumns. Implementation of the algorithms using PHP programming language.

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The use of information technology is very useful for today’s life and the next, where the human facilitated in doing a variety of activities in the life day to day. By the development of the existing allows people no longer do a job with difficulty. For that, it takes a system safety home using system technology Web-based and complete video streaming CCTV (video streaming) a person can see the condition of his home whenever and wherever by using handphone, laptops and other tools are connected to the Internet network. This tool can facilitate someone in the monitor at home and control equipment the House as open and close and the lock the gate, turning on and off the lights so homeowners are no longer have to visit their home and fear the state of the House because fully security and control in the House was handled by the system. based on the above problems Writer try to design work system a tool that can control the simulation tools home using two Microcontroller is Attiny 2313 and Atmega16.

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