Judul: Analisis performance algoritme paralel block cipher RC6 menggunakan message passing interface (MPI)
Abstrak: RC6 algorithm is a block cipher algorithm, which is one of the finalists in the AES competition. One of the RC6 algorithm parameters is the size of the block, where a larger block size is used the more time required to perform encryption-decryption. In this research the RC6 algorithm would be parallelized by dividing the data to each processor and the performance of the RC6 algorithm would be analyzed. Parallel implementation of the RC6 algorithm uses Message Passing Interface (MPI). The purpose of this research is to measure and analyze the performance of parallel RC6 algorithm. This research uses 4 computer with Linux operating system. This research uses files ASCII text and binary for the experiment. Each file will do the experiment three times repetition to take the average value. The results of this research show that execution time of parallel RC6 algorithm at the process of encryption and decryption is longer than execution time of sequential RC6 algorithm. For example, for file size of 249,149,712 bytes, encryption execution time of sequential RC6 algorithm is 17.91 seconds, whereas using the number of processors as many as 2, 4, 6 and 8, respectively are as follows 18.34 seconds, 20.37 seconds, 17.51 seconds and 18.93 seconds. The results of encryption execution time show that the encryption execution time by using the processor number of 4 is the slowest one. The speedup of parallel RC6 algorithm is less than one or smaller than the speedup of sequential RC6 algorithm. The speedup of parallel RC6 algorithm also not ideal because ideally speedup is equal to the number of processors used. The efficiency of parallel RC6 algorithm becomes lower along with more processor used. The resulting efficiency is far away from the optimum efficiency value, that is one, and it is not constant. To maintain the efficiency values if the number of processors is increased from p to p ' the input size should be increased in fraction of p'2 / p2. The cost of parallel RC6 algorithm increases as more processors are used. The resulting cost greater than the optimal cost value that is equal to Ts. The resulting overhead values become greater when the number of processors are increased. The results of this research indicate that the RC6 algorithm is not good when it is parallelized with domain decomposition method and using MPI. This is because the RC6 algorithm has a fast computational process, but it has the long communication time, so the total execution time of parallel RC6 algorithm longer than sequential RC6 algorithm.
Keyword: block cipher, RC6 algorithm, parallel, Message Passing Interface (MPI), Linux, Performance metric, execution time, speedup, efficiency, isoefficiency

Judul: Analisis dan Implementasi Algoritme Advanced Encryption Standard (AES) Secara Paralel
Abstrak: AES is an algorithm for symmetric key cryptography. AES is expected to replace Data Encryption Standard (DES) as a recognized standard for various applications. The complexity of AES encryption and decryption process is O(n), it has fast computation in both encryption and decryption but its execution time will increase as the input data increase. In this research the AES algorithm would be parallelized by dividing the data to each processor (domain decomposition) and by dividing the constituent computing of AES to each processor (functional decomposition), and their performance would be analyzed. Parallel implementation of AES algorithm uses Message Passing Interface (MPI). The objectives of this research are to measure and analyze the performance of parallel AES algorithm using performance metrics. The best result of the parallel AES algorithm in this research is in the decryption process using domain decomposition method. A file with 118.525 MB size has 127.227 seconds decryption execution time using sequential AES algorithm, whereas using 16 processors, its decryption execution time is 34.896 seconds. The speedup is 3.646 and the efficiency is 0.228. This result is not good enough because the speedup is not equal to the number of processors used and the efficiency is below one. This is because the AES decryption in this research has a fast computational process, yet it has a big overhead for data communication. The worst result of the parallel AES algorithm is in the decryption process using functional decomposition method. Using the same file and three processors, the decryption execution time is 168.089 seconds. The speedup is 0.755 and the efficiency is 0.252. This is due to the fact that computing process decomposition is not equally distributed among the processes and the use of MPI blocking communication routine which cause a big overhead for data communication. Both parallel algorithms used in this research are not cost-optimal
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Judul: Konsep Taman Rumah Adat Bagas Godang Berbasis Budaya Mandailing, Kabupaten Mandailing Natal, Sumatera Utara.
Abstrak: Kekayaan suatu bangsa tidak terbatas pada kekayaan sumber daya alamnya akan tetapi juga kekayaan budayanya. Taman rumah tradisional merupakan salah satu kekayaan budaya di Indonesia yang dapat menjadi identitas dari suatu budaya tersebut. Budaya Mandailing sudah dikenal sejak abad ke-14 M. Hal tersebut dibuktikan dengan penyebutan nama Mandailing di kitab Negara Kertagama, karangan Mpu Prapanca. Budaya Mandailing awalnya banyak dipengaruhi oleh kepercayaan animisme dan dinamisme yang disebut sipelebegu. Kemudian perkembangan selanjutnya budaya Mandailing bersinggungan dengan Hindu- Budha. Akan tetapi Islam membawa pengaruh yang sangat besar terhadap budaya Mandailing. Hal tersebut dibuktikan dengan adanya filosofi hombar do adat dohot ibadat yaitu adat tidak boleh bertentangan dengan agama. Dalihan Natolu merupakan konsep kekerabatan yang banyak mempengaruhi nilai-nilai kehidupan masyarakat Mandailing. Konsep Dalihan Natolu menjadi konsep dasar yang mempengaruhi pola permukiman adat Mandailing. Dalihan Natolu terdiri dari mora, anak boru, dan kahanggi. Hubungan antara ketiga komponen ini menentukan jarak antar rumah di permukiman adat. Suatu permukiman terdapat Rumah tinggal yang merupakan landmark dari berdirinya suatu permukiman. Rumah tinggal ini disebut Bagas Godang. Bagas Godang bagi masyarakat Mandailing bukan hanya sebagai rumah tinggal seorang raja atau tunggani huta. Godang bermakna sebagai rumah bagi seluruh marga di huta adat tersebut. Bagi masyarakat Mandailing raja tidak hanya berperan sebagai penguasa huta adat, akan tetapi mereka adalah orang yang dituakan yang dapat menyelesaikan berbagai masalah di permukiman adat tersebut. Komplek Bagas Godang terdiri dari Bagas Godang atau kediaman raja, Sopo Godang yaitu tempat peyimpanan instrument alat music dan musyawarah, serta biasanya memiliki Sopo Eme atau lumbung padi, serta Alaman Bolak Selangseutang merupakan halaman.
Keyword: Bagas Godang, taman vernakuler, desain taman, taman tradisional, rumah tinggal