Judul: Upaya Rehabilitasi Mangrove dalam Rangka Pengembangan Ekowisata di Pantai Pejarakan, Bali
Abstrak: Pantai Pejarakan memiliki ekosistem mangrove yang luas, hasil penelitian sebelumnya menunjukkan daerah ini sesuai untuk dikembangkan menjadi destinasi ekowisata. Penelitian ini dilakukan dengan tujuan menyusun rencana aksi pengembangan kawasan rehabilitasi guna menjadikan pantai Pejarakan sebagai lokasi ekowisata. Lokasi penelitian berada di kawasan mangrove pantai Pejarakan, Buleleng, Bali. Data yang diambil berupa data kesehatan mangrove, kualitas lingkungan serta persepsi masyarakat tentang konservasi dan ekowisata mangrove. Berdasarkan hasil evaluasi dan matriks rehabilitasi didapatkan rencana aksi yang berbeda untuk tiap kategori. Hasil evaluasi terhadap upaya rehabilitasi yang telah dilakukan sebelumnya menunjukkan Rhizophora mucronata dan Rhizophora apiculata menjadi jenis yang paling sesuai dengan teknik penanaman rumpun berjarak. Rencana tapak yang diusulkan disesuaikan dengan studi kesesuaian ekowisata mangrove sebelumnya.
Keyword: mangrove, rehabilitasi, lingkungan, Pejarakan

Judul: Mangrove Ecosystem Management Strategy for Sustainable Marine Ecotourism in Pejarakan Village, Buleleng Regency
Abstrak: Ekosistem mangrove selain berfungsi secara fisik, juga memiliki fungsi sebagai penyeimbang ekologi dan manfaat ekonomi. Kawasan pesisir Desa Pejarakan termasuk dalam kawasan pariwisata Kabupaten Buleleng yang saat ini pemanfaatan eksisting masih berupa pertambakan garam rakyat serta tambak udang dan Keramba Jaring Apung (KJA) oleh salah satu perusahaan bernama PT. Agung Menjangan Mas yang berlokasi di Banjar Garuda Desa Pejarakan Kabupaten Buleleng. Sejalan dengan aktifitas perseroan, terdapat area pesisir perusahaan yang tidak digunakan sebagai area budidaya dan belum dimanfaatkan hingga saat ini. Tujuan penelitian adalah menyusun strategi pengelolaan ekosistem mangrove untuk pengembangan ekowisata pesisir di Desa Pejarakan. Guna mencapai tujuan tersebut, maka dilakukan identifikasi potensi berupa sumberdaya mangrove, estimasi nilai ekonomi ekowisata dan analisis sosial dan kelembagaan. Metode yang digunakan dalam identifikasi potensi ekosistem mangrove tersebut adalah spot check method, data ekonomi dengan pendekatan benefit transfer dan data sosial dan kelembagaan melalui depth interview terhadap key person stakeholder berbasis purposive sampling. Adapun analisis yang digunakan adalah Daya Dukung Kawasan (DDK), Indeks Kesesuaian Wisata (IKW), Willingness to Pay (WTP), Travel Cost Method (TCM) dan Stakeholder Mapping serta Gap Analysis. Hasil penelitian diperoleh jenis mangrove yang teridentifikasi sebanyak sembilan jenis dan lima jenis biota asosiasi pada area seluas ± 15 Ha tersebut. Indeks Kesesuaian Wisata (IKW) dari empat area penelitian dua diantaranya termasuk dalam ketegori sesuai (S) yaitu pada area II dan III sedangkan dua area lainnya tidak sesuai (TS). Daya Dukung Kawasan (DDK) sebanyak 177 orang/hari dengan nilai rata-rata WTP ketika diselenggarakan ekowisata mangrove adalah Rp 78.226,00 per wisatawan dan nilai manfaat keberadaan ekowisata tersebut adalah Rp 1.661.520.240,00/tahun dengan asumsi kunjungan wisatawan saat weekend dan hari libur. Strategi pengelolaan berdasarkan analisis stakeholder mapping dikemukakan berupa pengelolaan berbasis pemberdayaan masyarakat, yaitu golongan key players pada peta stakeholder berperan sebagai koordinator dalam merencanakan pengembangan konsep ekowisata, adapun stakeholder tersebut yaitu; Desa Adat Pejarakan, Dinas Pariwisata, Dinas Lingkungan Hidup dan PT. Agung Menjangan Mas. Berdasarkan analisis gap, mengacu pada kondisi terkini dan kondisi ideal, teridentifikasi strategi pengelolaan secara teknis berupa; (i) upaya penyelenggaraan dan/atau pelibatan pelatihan pengawasan SDKP bagi Pokmaswas terkait oleh UPT pengampu (ii) peningkatan kinerja pokdarwis terkait kebersihan dan ekowisata melalui dukungan BUMDES Desa Pejarakan dan pelatihan pengelolaan wisata oleh dinas pariwisata, (iii) pengembangan ekowisata terpadu berbasis Desa Wisata Pejarakan dan (iv) percepatan pengesahan aturan awig-awig sebagai Perdes oleh Desa Dinas Pejarakan., In addition to functioning physically, mangrove ecosystems also have other functions, namely as ecological balancers and as sources of economic benefits. The coastal area of Pejarakan Village is included in the tourism area of Buleleng Regency, and currently, the existing utilization is still limited to the form of aquaculture areas (shrimp and salt), where one of which is managed by PT. Agung Menjangan Mas, with shrimp cultivation located in Banjar Garuda Pejarakan Village. In line with the company's activities, there are coastal areas owned by the company that are not used as cultivation areas and have not been utilized optimally. The study aims to develop a strategy for mangrove ecosystem management as ecotourism on the coast of Pejarakan Village. To achieve this goal, mangrove resource potential is identified through economic value estimation and
Keyword: Mangrove ecotourism, tourism suitability index, gap analysis

Judul: Algorithm construction of HLI hash function
Abstrak: Cryptography is a study of mathematical techniques related to aspects of information security regarding on confidentiality, data integrity, entity authentication, and data origin authentication. Data integrity is a service, which is associated with the conversion of data carried out by unauthorized parties. To maintain data integrity, one can use hash functions. An hash function is a computationally efficient function to map an arbitrary length bitstring to a fixed length bitstring called as hash value. The use of hash function in maintaining the information integrity and authentication is in digital signatures, virus protection, and software distribution. Illustration of the hash function in the integrity and authentication of information that is emailed as follow. The sender sends the information and hash value to the recipient. If the hash value of the information is equal to the hash value that is sent by the sender, then information has not been changed. Otherwise the information has been changed. An hash function has two properties, one way and collision resistance. An hash function is called one way if it is computationally infeasible to find any input such that when given any hash value . Meanwhile an hash function is called collision resistant if it is computationally infeasible to find any two inputs where such that . The purpose of this study is to construct a HLI hash function algorithm, to analyze the speed and security of the hash functions as a results of construction. Furthermore, it is to compare it with SWIFFT. Hash function is constructed based on the result of algebraic operations on modular polynomial ringwith . Modular polynomial ring noted as is a set of all polynomials of degree at most with coefficients in . can be represented as a set of integer vector of modulo in dimension . So, it is simple to implement in a computer. In vector operations, is lattice . Furthermore, alattice that is defined from certain polynomial ring is called ideal lattice. HLI hash function is consists of addition and multiplication algorithm in the ring. Addition algorithm consists of sumation operations of modulo and multiplication consists of multiplication operations of modulo . Generally, algorithm of HLI hash function consists of multiplication operations of modulo and addition operations of modulo . However, if the input is binary number then multiplication algorithm only consists of multiplication operation of modulo , so algorithm of HLI hash function consists of multiplication operations of modulo and addtion operations of modulo . An hash function is secured if it has two properties, i.e., one way and collision resistance. HLI hash function hash is one way, it is following the proof of Micciancio. It is has collision resistant because of polynomial is irreducible over and monic. Moreover, it is proved that for every unit vector , the vector is small vector. If the input of hash function is a binary number then HLI hash function only involves addition operations of modulo . So the time that used almost same with SWIFFT. The excellence of HLI hash function is the key size smaller than SWIFFT. This effect on
Keyword: hash function, modular polynomial ring, lattice