Judul: Kontribusi Ekowisata dalam Upaya Konservasi Ekosistem Mangrove di Pulau Pramuka, Kepulauan Seribu
Abstrak: Ekosistem mangrove Pulau Pramuka saat ini dimanfaatkan sebagai kawasan wisata. Kegiatan wisata dapat meningkatkan kegiatan manusia sehingga dapat mempengaruhi kegiatan konservasi dan akivitas wisata. Penelitian ini bertujuan untuk menganalisis kontribusi ekowisata dalam upaya konservasi ekosistem mangrove di Pulau Pramuka. Penelitian dilakukan di Pulau Pramuka pada Maret hingga April 2019. Pengambilan data mencakup data ekologi mangrove dan sistem manajemen yang telah dilaksanakan terhadap ekosistem mangrove dan kawasan wisata. Kontribusi ekowisata untuk konservasi masih perlu ditingkatkan agar upaya pemanfaatan dan konservasi mangrove dapat dioptimalkan. Sumberdaya mangrove saat ini belum sesuai untuk pemanfaatan kegiatan wisata dan belum diterapkannya sistem daya dukung dapat mengancam kelestarian lingkungan. Variabel K5, E1, dan E1 menunjukan bahwa masyarakat Pulau Pramuka mengerti bila perlindungan terhadap ekosistem mangrove dapat mendatangkan manfaat salah satunya yaitu pemanfaatan sebagai wisata mangrove. Terdapat tujuh rekomendasi pengelolaan agar kegiatan ekowisata untuk konservasi mangrove di Pulau Pramuka dapat berjalan lebih efektif.
Keyword: ekowisata, mangrove, pengelolaan, Pulau Pramuka

Judul: Management of Mangrove Conservation Areas for Ecotourism Activities in Pramuka Island, Seribu Islands
Abstrak: Ekosistem mangrove Pulau Pramuka merupakan kawasan konservasi yang dijadikan sebagai kawasan ekowisata tracking mangrove. Kegiatan wisata tersebut tentu dapat meningkatkan kegiatan ekonomi. Kawasan wisata mangrove tersebut memiliki infrastruktur yang rusak disebabkan kurangnya perawatan oleh pihak taman nasional karena adanya pandemi. Tujuan dilakukan penelitian ini untuk menganalisis kesesuaian wisata dan mengestimasi nilai valuasi kesediaan membayar untuk perbaikan kawasan ekowisata tracking mangrove di ekosistem mangrove Pulau Pramuka. Pengambilan data yang dilakukan mencakup ekologi mangrove, pendapat wisatawan terkait kesediaan membayar perbaikan kawasan tracking mangrove, dan pandangan masyarakat dengan hadirnya ekosistem mangrove dan wisata yang ada didalamnya. Indeks kesesuaian wisata yang diperoleh bahwa kawasan mangrove Pulau Pramuka masih belum sesuai untuk dijadikan kawasan wisata karena faktor ketebalan dan jumlah jenis mangrove yang masih rendah. Pelancong atau wisatawan yang berkunjung mayoritas bersedia mendukung keberlanjutan wisata di ekosistem mangrove dengan bersedia membayar jasa lingkungan untuk pembangunan tracking mangrove dengan perolehan total WTP pembangunan sebesar Rp. 982.766.400/tahun dan diperoleh dengan metode open endded. Tingkat pandangan serta pemahaman masyarakat terhadap mangrove sudah masuk kategori tinggi dan pendekatan untuk pengelolaan kawasan mangrove dapat dilakukan dengan mendekati masyarakat dari kategori pendidikan SMA keatas., Pramuka Island mangrove ecosystem is a conservation area that is currently used as a mangrove tracking ecotourism area. These ecotourism activities are certainly expected to increase economic activities. However due to covid-19 pandemic there was of lack of maintenance by national park amanagement authority that leads to infratstructure damages. The purpose of this research is to analyze the suitability of tourism areas and estimate the valuation of willingness to pay for the improvement of mangrove tracking ecotourism areas in the Pramuka Island mangrove ecosystem. Data collected were included mangrove ecology, tourist willingness to pay for mangrove tracking facility improvements, and community perspectives on the presence of mangrove ecosystems and tourism activities. According to tourism suitability index analysis, Pramuka Island mangrove area is still not suitable for a tourism area due to the low score of mangrove ecosystem thikness and low number of mangrove species biodiversity. The majority of tourists are willing to support the sustainability of tourism in the mangrove ecosystem by paying environmental services to reconstruct mangrove tracking facility. Based on open ended method, the total willingness to pay (WTP) for reconstructing mangrove tracking facilities is amounted to Rp. 982,766,400 / year. The level of community perspective and understanding to mangroves function and benefit is already in the high category and managing this mangrove area management can be conducted by involving local people from the high school education category and above.
Keyword: ecotourism, mangroves, perception, Pramuka Island, WTP

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