ISSN 2278-3091 Edy Victor Haryanto S, International Journal of AdvancedVolume Trends 9, No.4, in Computer July – AugustScience and 2020 Engineering, 9(4), July – August 2020, 4671 – 4677

International Journal of Advanced Trends in Computer Science and Engineering Available Online at http://www.warse.org/IJATCSE/static/pdf/file/ijatcse6 9942020.pdf https://doi.org/10.30534/ijatcse/2020/69942020

Optimizing the Confidentiality of Lecturer Database using Elgamal Algorithm

Edy Victor Haryanto S Faculty Engineering and Computer Science, Universitas Potensi Utama

 not all employees who are given permission to access the ABSTRACT database understand the existing database flow to avoid data Each Higher Education Institution must have many theft, data destruction and others et cetera, until the databases, one of which is a database of lecturers who store implementation of cryptographic algorithms by the the confidentiality of data and information from lecturers as administrator of the records in the database with the aim of instructors. Securing lecturer databases is needed to protect making the stored records more confidential and difficult to lecturer data and information from database theft. Creating read by others [5]. an optimal system in securing lecturer databases to avoid Sometimes the database is also stored in the Cloud Server, the individuals who have no right to access and process data and information owner saves the information on a trusted server. information. The lecturer database processed in this study Most people believe that the cloud is a dangerous place and uses the ElGamal algorithm with key formation using primes once you save your information to the cloud, you lose and solving the problem requires discrete logarithmic complete control over it. The information owner cannot trust calculations. The keys used in this algorithm are public keys the cloud server to control secure access to information. In and private keys. The results of testing this method is the this way, the problem of safe access to information has turned encrypted lecturer database. ElGamal's algorithm is very into the most basic testing problem in storage distributed by helpful in securing the lecturer database at the Universitas the general public. So any ordinary security advances cannot Potensi Utama. be linked directly to him [6]. One mechanism to improve data security in databases is to use Key words: database, encryption, algorithm, elgamal, encryption technology [7]. The data stored in the database is decryption, cryptography. modified so that it is not easy to read. So encryption is a process carried out to secure a data (called plaintext) into 1. INTRODUCTION hidden data (called ciphertext). Ciphertext is data that cannot be read easily [8]. Utilization of computer applications in a company or One method that can be used for database security is the organization today is a necessity. Almost in all fields of work Elgamal Algorithm. The Elgamal algorithm invented by using tools in the form of computer applications [1]. Egyptian scientists [9], namely Taher Elgamal in 1985, is a Computer system security is becoming increasingly important public-key cryptographic algorithm. Elgamal algorithm as the development of computerized business processes. process consists of three processes, namely the process of key Computerized business process is a business process that most formation, the encryption process, and the decryption process. of its activities use computer technology and make the Elgamal cryptography was initially used for digital signature computer as a medium for storing important data so that it can requirements, but was later modified so that it could be used be said that computer media is an important factor in the for security such as encryption and description [10]. Elgamal business processes that are carried out. Computer system cryptography is used in security software developed by GNU, security is the focus not only of the computer device, but also the PGP program, and in other security systems [11]. the security of the network, software or application programs ElGamal security is based on a discrete logarithmic problem and database security [2]. to encrypt and decrypt messages separately. An intruder who Security and confidentiality of data stored in a database is one attempts to decrypt a disconnected message can try to recover important aspect of an information system, such as the data is the private key. For this purpose logarithms need to be safe from information leakage [3]. Security of computer calculated. There is no actual method for this, given the networks connected to databases no longer guarantees data specific needs of the initial group are met [12]. security because data leaks can be caused by insiders or The research aims to optimize the security of database parties directly related to databases such as database processing that is used in the database security application of administrators [4]. lecturers using the Elgamal algorithm at the Potential Main Database security can be done in various ways, starting from University. limiting user access rights to the database itself, using field names that are only understood by the administrator so that

4671

Edy Victor Haryanto S, International Journal of Advanced Trends in Computer Science and Engineering, 9(4), July – August 2020, 4671 – 4677

the system is to change the raw data that has been obtained 2. RESEARCH METHODOLOGY into data that is ready to be processed so that the expected results of the processing can be as expected. The research methodology will greatly assist the writer in the g. Implementing Elgamal Algorithm, the data obtained, then work process of solving problems. This study has several analyzed and implemented in order to produce useful stages in the implementation of activities contained in the information. At this stage data processing is carried out to order of research activities, namely purpose logarithms need secure the lecturer database at the Potential Main to be calculated. There is no actual method for this, given the University. In accordance with data processing, the specific needs of the initial group are met [12]. The research implementation phase is tested by applying the Elgamal aims to optimize the security of database processing that is algorithm to secure the database of the designed used in the database security application of lecturers using the application. Elgamal algorithm at the Potential Main University. h. Conduct Testing, at this stage, the results of data analysis Identifying problems, analyzing problems, determining that has been previously processed will be tested using the goals, studying literature, collecting data, designing systems, specified application. Elgamal Algorithm Testing can be implementing Elgamal algorithms on database security, done by trying the encryption and decryption process of the testing and making conclusions. lecturer database at the Universitas Potensi Utama. The 2.1. Sequence of Research Activities approach taken by writing in testing the system made is Black Box Testing where this test aims to show the The sequence of activities is the stages that will be carried out software's function of how it operates, whether the in order to solve the problem that will be discussed. The encryption and decrypt process runs correctly and the sequence of activities from this study can be seen in sequence application can be used by the user. of research activities below: i. Making Conclusions, after being tested, at this stage the a. Identifying Problems, the problem identified in this study database security cryptographic application passes the was to optimize the safety of lecturer databases at the testing phase and is ready for use by Windows users. Do not University of Potentials by applying the Elgamal algorithm rule out the possibility of this system experiencing changes to the process of encrypting and decrypting existing when it has been used by users. Changes can occur due to databases. errors that appear and are not detected during testing. The b. Analyzing Problems, the problems found will then be support or maintenance stage can repeat the development analyzed. The step in the problem analysis process is the process starting from specification analysis to changes to step to understanding the problem that has been existing information systems, but not to creating new determined. By analyzing the problems that have been information systems. determined, it is hoped that the problem can be understood properly. Analysis of the problem in this study was carried 2.2. Computer Security out by applying the Elgamal algorithm for the encryption The field of computer security is continuously experiencing and decryption process into the lecturer database system so extraordinary developments because information technology as to produce a more optimal lecturer database security. has an increasingly high influence on how we work, c. Determine the Goals, based on an understanding of the communicate, shop and enjoy entertainment [13]. Along with problems that have been analyzed, the next step is to this development, the threats to our computer security are determine the objectives to be achieved in this study. In this increasing, both physical and non-physical threats such as goal the target to be achieved, especially those that can security holes in the operating system, attacks on networks, overcome existing problems, is to produce a database viruses, and others. In building an internet-based network security application for lecturers at the Universitas Potensi system, security issues are absolutely necessary. A system Utama using the Elgamal algorithm. built without a good security system is the same as inviting a d. Studying Literature, studying the literature that will be thief to enter our house and let him take everything we have used as reference material in this research. The literature [14]. Often when building a system, we find various used is from scientific journals, learning modules and vulnerabilities in our system. But we consider it a small thing books on cryptography in particular relating to the because we do not consider it a security hole (hole). We are application of the Elgamal algorithm. The literature will be not aware that these small vulnerabilities are used by people a guideline for conducting research to assist and facilitate who are not responsible for carrying out their crimes [15]. the research process. 2.3. Information System Security e. Collecting Data, the method of data collection is done by requesting data from the lecturer admin about the lecturer One of the commonly used ways to secure information is to database at Universitas Potensi Utama, taking data from regulate access to information through an "access control" books and journals about database security. From this data, mechanism. Implementation of this mechanism, among it will be used as a reference in making lecturer database others, by using "password" [16]. To further enhance the security applications. security of information systems, protection can be added. This f. Designing the System, at this stage the data collected is protection can be in the form of filters (in general) and more then designed into a system that will be processed and specifically is a firewall. Filters can be used to filter e-mail, implemented with predetermined methods. The design of information, access, or even at the packet level. One 4672

Edy Victor Haryanto S, International Journal of Advanced Trends in Computer Science and Engineering, 9(4), July – August 2020, 4671 – 4677 mechanism for increasing security is to use encryption Internet administration network as shown in the figure 2 technology. The data that you send is modified so that it is not below [11]. easily intercepted. Many services on the Internet still use "plain text" for authentication, such as using a pair of userid and password. This information can be seen easily by the tapping (sniffer) program [17]. Following the information system security methodology (figure 1)is described in the form of a security level pyramid [18].

Figure 2: Network Security Model A network security analysis system implements a high-speed and high-volume data volume analytic framework that engulfs and analyzes a variety of network data, such as Net Flow data, DNS data, and security and management information data [19]. The system detects, categories, and reports abnormal activity. This system applies natural language processing (NLP) techniques that examine network analysis content and time series to establish and maintain a

Figure 1: Security Level Pyramid network condition condition model (for example, "normal" or nominal). The system analyzes its multi-dimensional There are 5 levels of Information Systems Security, namely perspective of network activity [20]. [17]: 2.5. Elgamal Algorithm a. Security level 0: physical security, is the initial security of computer security. Physical security only focuses on The Elgamal algorithm was discovered in 1985 by an physical features such as door locks, CCTVs, ID cards and Egyptian scientist, Taher Elgamal. Elgamal algorithm is an so on. If physical security is not maintained properly, then algorithm based on the concept of a public key. This data or even computer hardware cannot be secured. algorithm is generally used for digital signatures, but then b. Level 1 security: consists of database security, data modified so that it can be used for encryption and decryption. security, computer security, device security, application The security of the Elgamal algorithm lies in the difficulty of security. Only people who have the authority can access calculating discrete logarithms in large prime modules, so all the security mentioned earlier. Examples such as the that efforts to solve these algorithm problems are difficult to admin of a computer that stores various data and solve [21]. This algorithm has the advantage of generating information. keys using discrete logarithms and decryption encryption c. Level 2 security: network security, computers connected to methods that use large computational processes so that the networks such as LAN, WAN or the internet are very encryption results are twice the original size [22]. The vulnerable to security problems because computers can be weakness of this algorithm is that it requires a large resource accessed by client computers, therefore level 2 security because the ciphertext is generated twice the length of the must be designed so that network leaks do not occur, plaintext and requires a processor that is able to do large illegal access that can damage security of these data. computations for large-scale logarithmic calculations [23]. Therefore, after finishing level 1 security, level 2 security is designed so that no unwanted things occur such as 3. RESULTS AND DISCUSSION network leaks, illegal access, and other illegal actions. The issue of database security and confidentiality is one d. Level 3 security: information security, security that is important aspect of an information system. An information is sometimes overlooked by the admin such as leaving a only intended for certain parties, it is related to how the password on paper or giving a password to a friend, so information cannot be accessed by unauthorized persons. eating can be a very fatal thing because it can be misused. Security of files on the database can be done by using several e. Security level 4: is security that covers the whole of the asymmetric algorithms that can lock database files, including computer system. If level 1-3 has been executed properly, the Elgamal algorithm [24]. In this case, there are still many level 4 has been fulfilled. But it does not rule out the people who do not understand how to access or secure possibility that illegal things can occur such as an intruder database files so that the data contained in them cannot be or data destruction, etc. seen by others. This is due to the difficulty of computer 2.4. Network Security security procedures when using facilities provided by each operating system. For that, we need an application that can The network security model shown by a message will be easily and quickly lock and secure the user's computer using exchanged starting from one point to another through the keywords entered into it. 4673

Edy Victor Haryanto S, International Journal of Advanced Trends in Computer Science and Engineering, 9(4), July – August 2020, 4671 – 4677

Therefore we need a database security system that aims to f. γ and δ (ciphertext) (not secret) improve data security, protect data or messages from being There are 3 stages carried out in applying the Elgamal read by unauthorized parties, and prevent unauthorized method, namely the formation of keys, the encryption process parties from inserting, deleting, or changing data and the decryption process. [25][26][27]. In terms of database security techniques, many A. Key Formation Process cryptographic methods can be used. The cryptographic The key formation process is the process of determining a methods have their own techniques and methods. The steps number which will then be used as a key in the message for each method are different, both in terms of length and encryption and decryption process. The key for encryption complexity. One cryptographic method that can be used is the consists of the values p, g, y while the key for decryption Elgamal method. Then it is necessary to do more in-depth consists of the values x, p. Each value has a requirement that research on the use of the Elgamal method applied to database must be met [31][32][33]. security to achieve a high level of security. The steps in making a key are as follows: 3.1. Problem Solving Strategies a. Select any prime number p (p can be shared among group The problem solving phase is carried out to start from the members). process of analysis, design, evaluation and improve the b. Choose two random numbers, g and x, with the terms g < p system in accordance with needs, so that the system being and 1 ≤ x ≤ p - 2. made can be utilized optimally[28][29][30]. In this study c. Calculate y = gx mod p. using the Elgamal method for cryptographic techniques as a The results of this algorithm: way to secure a lecturer database at Universitas Potensi - Public Key: triple (y, g, p) Utama, Medan. - Private Key: double (x, p) Stages of searching for sources of knowledge or data are done From the steps above, the public key used for encryption is the through literature studies and interviews from: value of p, g, y and the private key used for decryption is the a. Journals related to database security and the Elgamal value x, p. The p, g, y values are not confidential while the x method. values are confidential. b. Books on database security and the Elgamal method. This following is flowchart of the process of forming the c. A trusted website that contains matters relating to how to Elgamal method is key. secure a database using the Elgamal method. d. Direct interview to get data to the admin lecturer at Universitas Potensi Utama, Medan regarding the lecturer database that is managed. Sources of knowledge and data obtained from this study are expected to be valid knowledge and data and can be used in the development of lecturer database security applications at the Universitas Potensi Utama. 3.2. Application of the Elgamal Method

With the many exchanges of information that occur, so many people who want these information for personal and group interests. This can happen if there is no high level of security from the exchange of important information. Based on these problems, the system to be built is a database security system that functions to secure database information in the form of lecturer data available at the Unviersitas Potensi Utama from irresponsible tappers. Then a database security is needed, in this case the database security is done by using the Elgamal method as the encryption and decryption process.

In this study, the author tries to create a database security application using a combination of Elgamal methods. By utilizing this method, it is hoped that a database security application can be developed that allows the user to encrypt the database with the Elgamal method and can decrypt the encrypted database. The properties of the Elgamal method are as follows: a. Primes, p (not secret) b. Randoms, g ( g < p) (not secret) c. Random, x (x < p) (secret, private key) x d. y = g mod p (not secret, public key) e. m (plaintexts) (secret) Figure 4: Key Formation Flowchart

4674

Edy Victor Haryanto S, International Journal of Advanced Trends in Computer Science and Engineering, 9(4), July – August 2020, 4671 – 4677

Example: Example: Key Generation (By Budi) Encryption (By Ani) For example p = 2357, g = 2, dan x = 1751. For example message m = 2035 (m value is still in the interval Calculate: y = gx mod p = 21751 mod 2357 = 1185 [0, 2357 – 1]). Result : Public Key: (y = 1185, g = 2, p = 2357) Bob chooses random numbers k = 1520 (the k value is still in Private key: (x = 1751, p = 2357). the interval [0, 2357 – 1]). B. Encryption Process Ani calculates: γ = gk mod p = 21520 mod 2357 = 1430 The encryption process is the process of changing the original δ = ykm mod p = 11851520 x 2035 mod 2357 = 697 message (plaintext) into a secret message (ciphertext). In this So, the resulting ciphertext is (1430, 697). process public keys (p, g, y) are used. The steps in encrypting Ani sent this ciphertext to Budi messages are as follows: a. Arrange plaintext into blocks m1, m2, ..., (the value of each C. Decryption Process block in the interval [0, p - 1]). The decryption process is the process of changing a secret b. Change the message block value to ASCII value. message (ciphertext) into an original message (plaintext). In c. Choose the random number k, which in this case is 1 ≤ k ≤ this process private keys (x, p) are used. The steps in p - 2. decrypting a message are as follows. d. Each block m is encrypted with a formula: a. Determination of gamma and delta values. The gamma γ = gk mod p value (γ) is obtained from ciphertext in odd order while δ = ykm mod p delta (δ) is in even order.. e. Arrange ciphertext in sequence γ1,δ1, γ2,δ2,...,γn,δn. b. Use x private key to count: f. The pairs γ and δ are ciphertexts for message blocks m. So, (γx)-1 = γp – 1 – x mod p ciphertext is twice the size of the plaintext. c. Calculate plaintext m with equation: Following is the encryption process flowchart: d. m = δ / γx mod p = δ (γx)–1 mod p e. Change the value of m obtained to ASCII value. f. Arrange plaintext in sequence m1,m2,...,mn. The following is a flowchart of the Elgamal method decryption process.

Figure 6: Decryption Process Flowchart Figure 5: Encryption Process Flowchart

4675

Edy Victor Haryanto S, International Journal of Advanced Trends in Computer Science and Engineering, 9(4), July – August 2020, 4671 – 4677

Example: Decryption (By Budi) 10. D. Anggraini and S. Juanita, “Aplikasi E-Arsip 1 / γx = (γx)–1 = γp – 1 – x mod p = 1430605 mod 2357 = 872. Pengamanan Pesan Elektronik Berbasis Web dengan m = δ / γx mod p = 697 x 872 mod 2357 = 2035 Mengimplementasikan Algoritma Kriptografi RSA dan Elgamal pada Klinik Dr. H. Hartono,” J. Ilm., 4. CONCLUSION vol. 6, no. 3, p. 122, 2018. After carrying out the stages of the research process regarding 11. S. Tayal, N. Gupta, P. Gupta, D. Goyal, and M. the security of lecturer databases at Universitas Potensi Goyal, “A Review paper on Network Security and Cryptography,” Adv. Comput. Sci. Technol., vol. 10, Utama, Medan using the elgamal algorithm, it can be no. 5, pp. 763–770, 2017. concluded that the elgamal algorithm can be used to convert 12. N. Kaur and H. Wadhwa, “Security Enhancement in the text contained in the database into a secret text Cloud Storage using ARIA and Elgamal (ciphertext) so that it cannot be read by data thieves. Algorithms,” Int. J. Comput. Appl., vol. 171, no. 9, pp. 19–23, 2017. REFERENCES https://doi.org/10.5120/ijca2017915116 13. M. S. Hasibuan, “Keylogger Pada Aspek Keamanan 1. M. Zayyadi, L. Supardi, and S. Misriyana, Komputer,” J. Teknovasi J. Tek. dan Inov., vol. 3, no. “Pemanfaatan Teknologi Komputer Sebagai Media 1, pp. 8–15, 2018. Pembelajaran Pada Guru Matematika,” J. Pengabdi. 14. U. Rahardja, Q. Aini, and N. P. L. Santoso, Masy. Borneo, vol. 1, no. 2, pp. 25–30, 2017. “Pengintegrasian YII Framework Berbasis API pada https://doi.org/10.35334/jpmb.v1i2.298 Sistem Penilaian Absensi,” SISFOTENIKA, vol. 8, 2. P. SAPTIAWAN, “RANCANG BANGUN no. 2, pp. 140–152, 2018. KEAMANAN SISTEM PENDATAAN GUDANG 15. J. R. Batmetan, “Analisis Perilaku Mahasiswa PTIK BERBASIS CLIENT SERVER MENGGUNAKAN di Unima dari Ancaman Keamanan Komputer,” ALGORITMA ATBASH, VIGENERE DAN 2018. AFFINE CIPHER,” 2018. 16. A. W. P. Putra, A. Bhawiyuga, and M. Data, 3. P. Priyono and P. Tarigan, “IMPLEMENTASI “Implementasi Autentikasi JSON Web Token (JWT) ALGORITMA TRANSPOSISI CIPHER DAN Sebagai Mekanisme Autentikasi Protokol MQTT VIGENGERE CIPHER UNTUK KEAMANAN Pada Perangkat NodeMCU,” J. Pengemb. Teknol. BASIS DATA DALAM JARINGAN KOMPUTER,” Inf. dan Ilmu Komput. e-ISSN, vol. 2548, p. 964X, Pelita Inform. Inf. dan Inform., vol. 16, no. 2, 2017. 2018. 4. A. Siburian, A. P. Harianja, T. Informatika, U. St, J. 17. B. Rahardjo, Berbasis Internet, vol. 0. 1999. Setia, and B. No, “Perancangan Aplikasi 18. M. S. Herawati and N. Mintarsih, “PENINGKATAN Pengamanan Basis Data Menggunakan Algoritma KEAMANAN APLIKASI KONTROL DENGAN Caesar Cipher,” vol. 02, no. 479, pp. 1–6, 2017. MENGGUNAKAN METODE FIREWALLDAN 5. A. Pengamanan, D. Keuangan, B. Desktop, and M. KASPERSKY ENDPOINT SECURITY 8,” UG J., Algoritma, “Aplikasi Pengamanan Database vol. 7, no. 11, 2016. Keuangan Berbasis Desktop Menggunakan 19. Y. Arta, “Implementasi Intrusion Detection System Algoritma Rc4 Dan Vigenere,” vol. 1, no. 1, pp. Pada Rule Based System Menggunakan Sniffer Mode 237–242, 2018. Pada Jaringan Lokal,” IT J. Res. Dev., vol. 2, no. 1, 6. S. Bade, S. Jadhav, and K. Pakhare, “A ROBUST pp. 43–50, 2017. MULTI AUTHORITY VERIFICATION IN CLOUD 20. P. J. Joyce and U. S. Ci, “( 12 ) United States Patent,” USING ELGAMAL ENCRYPTION SCHEME,” pp. vol. 2, 2019. 303–309. 21. A. Karima, L. B. Handoko, and A. Saputro, 7. T. Erlangga and D. Kusumaningsih, “Pemfaktoran Bilangan Prima pada Algoritme “IMPLEMENTASI ALGORITMA ADVANCED ElGamal untuk Keamanan Dokumen PDF,” J. Nas. ENCRYPTION STANDARD-128 (AES-128) Tek. Elektro dan Teknol. Inf., vol. 6, no. 3, pp. UNTUK PENGAMANAN DATABASE BERBASIS 252–258, 2017. DESKTOP PADA ICALTOYS,” SKANIKA, vol. 1, 22. A. M. H. Pardede, “Aplikasi Pengamanan File no. 2, pp. 565–569, 2018. Gambar Menggunakan Algoritma Elgamal,” J. Inf. 8. C. V. B. Sakti, “IMPLEMENTASI PENGAMANAN Syst. Dev., vol. 3, no. 2, 2018. DATABASE MENGGUNAKAN METODE 23. W. Sari et al., “ANALISA ALGORITMA BLOWFISH DAN AES PADA PERUSAHAAN,” ELGAMAL DALAM PENYANDIAN DATA,” vol. vol. 1, no. 1, pp. 366–372, 2018. 2, no. 1, pp. 60–70, 2018. 9. A. D. Haryono and P. F. Ariyani, “APLIKASI 24. G. A. Sahputra and T. Fatimah, “IMPLEMENTASI PENGAMAN BASIS DATA PADA NUKLINDO KRIPTOGRAFI DENGAN METODE LAB DENGAN ALGORITMA ELGAMAL DAN ALGORITMA ELGAMAL UNTUK KEAMANAN AFFINE CIPHER,” SKANIKA, vol. 1, no. 1, pp. DATABASE BERBASIS JAVA DESKTOP PADA 186–192, 2018. 4676

Edy Victor Haryanto S, International Journal of Advanced Trends in Computer Science and Engineering, 9(4), July – August 2020, 4671 – 4677

PT. MAKMUR SUPRA NUSANTARA,” SKANIKA, vol. 1, no. 1, pp. 309–315, 2018.

25. S. Sumarno, “Analisis Kinerja Kombinasi Algoritma Message-Digest Algortihm 5 (MD5), Rivest Shamir Adleman (RSA) dan Rivest Cipher 4 (RC4) Pada Keamanan E-Dokumen,” J. Sist. Inf. dan Ilmu Komput. Prima (JUSIKOM PRIMA), vol. 2, no. 1, 2018. 26. HARYANTO, Edy Victor, et al. Application of Method Threshold Secret Sharing in Securing Data. In: Journal of Physics: Conference Series. IOP Publishing, 2019. p. 012021. 27. Hariguna, T., Adiandari, A. M., & Ruangkanjanases, A. (2020). Assessing customer intention use of mobile money application and the antecedent of perceived value, economic trust and service trust. International Journal of Web Information Systems. http://doi.org/10.1108/IJWIS-12-2019-0055 28. Hariguna, T., & Ruangkanjanases, A. (2020). Elucidating E-satisfaction and Sustainable Intention to Reuse Mobile Food Application Service , Integrating Customer Experiences , Online Tracking , and Online Review, XXIX, 122–138. http://doi.org/10.24205/03276716.2020.704. 29. Hariguna, T., Maulana, W., & Nurwanti, A. (2019). Sentiment Analysis of Product Reviews as A Customer Recommendation Using the Naive Bayes Classifier Algorithm. International Journal of Informatics and Information Systems, 2(2), 48–55. 30. Imron, M., Hasanah, U., & Humaidi, B. (2020). Analysis of Data Mining Using K-Means Clustering Algorithm for Product Grouping. International Journal of Informatics and Information Systems, 3(1), 12–22. 31. Hariguna, T., & Rachmawati, V. (2019). Community Opinion Sentiment Analysis on Social Media Using Naive Bayes Algorithm Methods. International Journal of Informatics and Information Systems, 2(1), 33–38. 32. Santiko, I., & Subarkah, P. (2019). Comparison of Cart and Naive Bayesian Algorithm Performance to Diagnose Diabetes Mellitus. International Journal of Informatics and Information Systems, 2(1), 9–16. 33. Hariguna, T., Hung, C., & Sukmana, H. T. (2019). The antecedent of citizen intention use of e-government service. TELKOMNIKA (Telecommunication Computing Electronics and Control), 17(1), 202–209. http://doi.org/10.12928/TELKOMNIKA.v17i1.11588

4677