Judul: Analisis dan Implementasi Pembagian Rahasia Menggunakan Skema Ambang Shamir
Abstrak: key is used to keep secret in order not easily accessible by others. The key itself also requires a way to keep it from accessed by someone else. A threshold secret sharing scheme developed by Adi Shamir is one way to keep a secret key. This scheme's objective is to divide a secret key S into n parts, such that S is easily reconstructed from any t parts, but when less than t parts are known there is no information about the secret key can be obtained. This research's objectives are to explain how to share a secret using Shamir's threshold scheme, to analyze the security of Shamir's threshold scheme, and to implement Shamir's threshold secret sharing scheme using Wolfram Mathematica 10. Shamir threshold scheme consists of two stages, namely sharing stage and reconstruction stage. This scheme is computationally secure, since it works on integers modulo p, so that when only t – 1 parts of the secret number are known, it is very difficult to guess the value of S.
Keyword: Bogor Agricultural University (IPB), Lagrange interpolation, secret sharing scheme, cryptography

Judul: The Application of Recursive Algorithm on Shamir's Scheme Reconstruction for Cheating Detection and Identification
Abstrak: Perlindungan data informasi mutlak dibutuhkan untuk menangkal dan mengatasi beragam serangan yang mungkin dihadapi. Skema pembagian rahasia (SPR) yang menerapkan metode kriptografi di dalamnya dengan tujuan mempertahankan keamanan data rahasia oleh sekelompok pihak terpercaya adalah jawabannya. Konsep ini mulanya digagas secara individual oleh Shamir (1979) dan Blakley (1979) yang lebih familiar disebut sebagai SPR ambang batas-(t,n). Prinsipnya, pesan terenkripsi (secret) s didistribusikan oleh pihak terpercaya (dealer) kepada n partisipan pemegang kunci privat (shareholder) dan hanya jika terdapat sebarang subset t atau lebih partisipan saja maka pesan tersebut baru dapat dibaca. Share dalam konteks ini berupa kepingan-kepingan secret yang harus disatukan terlebih dahulu oleh dealer agar pesan dapat didekripsi. SPR menjadi solusi atas beragam risiko serangan yang mungkin terjadi, di mana share yang terlalu sedikit akan rentan hilang dan sebaliknya jika digandakan terlalu banyak dapat meningkatkan potensi kecurangan. Penelitian ini difokuskan pada empat tujuan utama, yaitu: (1) Memodifikasi skema Shamir pada fase pembagian share dan rekonstruksi secret dengan penerapan algoritme rekursif; (2) Mengonstruksi skema linear Shamir yang telah dimodifikasi untuk mendeteksi kecurangan dan mengidentifikasi pelakunya; (3) Membuktikan bahwa skema linear Shamir yang telah dimodifikasi memiliki efisiensi waktu yang tinggi; (4) Menganalisis tingkat keamanan deteksi dan identifikasi kecurangan dari skema yang diajukan. Penerapan algoritme rekursif pada skema linear berbasis Shamir dipilih sebagai metode utamanya. Bukan hanya pada fase rekonstruksi secret, namun sejak awal pada fase pembagian share, algoritme ini telah diintegrasikan satu sama lain dengan memanfaatkan suatu parameter detektor untuk menjamin nilai secret yang dicari adalah valid. Meski skema yang diperoleh akan jauh lebih sederhana karena memanfaatkan struktur matriks Vandermonde, namun aspek keamanan pada skema ini tidak berkurang sebab didukung oleh parameter detektor khusus yang dirumuskan dari algoritme rekursif untuk mendeteksi kecurangan dan mengidentifikasi pelakunya. Karenanya skema ini dijamin aman tanpa syarat (unconditionally secure). Selain adanya parameter detektor akan menjamin bahwa hanya partisipan yang jujur sajalah yang dapat merekonstruksi secret, skema ini juga memiliki efisiensi waktu yang tinggi (polynomial running time). Hal itu dikarenakan teknik rekursif dapat meningkatkan laju komputasi yang dibutuhkan dengan menghitung ukuran masukan n pada masing-masing algoritmenya. Dengan kata lain algoritme ini mampu mengatasi kekurangan pada penelitian-penelitian SPR linear Shamir sebelumnya. Karena semakin kompleks/rumit suatu algoritme yang dijalankan maka tentu akan semakin banyak waktu yang dihabiskan untuk menyelesaikannya., Information data protection is absolutely necessary to ward off and overcome various attacks that may be encountered. A secret sharing scheme (SSS) that implements cryptographic methods with the aim of maintaining the security of confidential data by a group of trusted parties is the answer. This concept first was conceived individually by Shamir (1979) and Blakley (1979) which is more familiar referred to as SSS threshold-(t,n). In principle, encrypted messages (secret) s are distributed by a trusted party (dealer) to n participants holding private keys (shareholders), and when there are any subset t or more participants then the message can only be read. Here, shares are secret pieces that the dealer must put together first so that the message can be decrypted. SSS is a solution to various possible attack risks, where too few shares will be vulnerable to lose and otherwise if
Keyword: cryptography, recursive algorithm, Shamir's linear scheme

Judul: Biology and ecology of the buffalo fly, haematobia exigua de meijere (diptera:muscidae)
Abstrak: The life history of the buffalo fly was observed at room temperature of 27°-29.5°C and at a relative humidity of 48-68 percent. The eggs hatched after 17-22 hours, with an average of 18 hours. First instar larvae measured 1.25 + 0.16 mm long and 0.27 + 0.037 mm wide. reach the second larval stage. It took 6-12 hours to the second instar larvae measured 2.676 +0.187 mm long and 0.353 +0.028 mm wide. The second instar took about 12-24 hours to reach the third larval stage. The third instar measured 6.833 + 0.189 mm long and 0.919 + 0.051 mm wide. It took about 2-3 days for the third instar to become pupae. Duration of the pupal stage was about 5-7 days before the adults emerged. Under laboratory condition, the buffalo fly completed its life cycle in 9.5 to 10.5 days, whereas under field condition it took 9-14 days with an average of 10.5 days. The growth ratio which was based on the measurements of the cephalo-pharyngeal skeleton of each instar was 1.797. The preoviposition period was 8-12 days and mating usually occurred on the 6th or 7th day. The longevity of the male was 29 days, whereas it was 32 days in the female. The range of egg production under laboratory condition was between 20-139 per female fly. The belly and hind legs of the carabao were the most preferred habitat either during cloudy and cool dry or shiny and warm day. When the weather was clear and the carabao was in the shade, the flies tended to be more distributed particularly on the shoulder, dewlap, back and horns. The carabaos had relatively fewer Musca sp. and Stomoxys calcitrans than cattle; never the less carabaos had a higher infestation of buffalo fly than cattle. Oviposition occured either during the day or night but the buffalo flies were more active during the night than in the day time. The effect of various lengths of exposure time of manure in relation to the oviposition was profound. observed, the maximum number of the buffalo flies was occurred when the dung was exposed for 30 minutes. With increasing time of exposure the number and variety of insects also increase. It was evident that Sepsidae and psychodidae were the most dominant insects emerging from the dung. The number of buffalo flies also increased with increasing
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