Succinct Blind Quantum Computation Using a Random Oracle

In the universal blind quantum computation problem, a client wants to make use of a single quantum server to evaluate $C|0\rangle$ where $C$ is an arbitrary quantum circuit while keeping $C$ secret. The client's goal is to use as few resources as possible. This problem, first raised by Broadbent, Fitzsimons and Kashefi [FOCS09, arXiv:0807.4154], has become fundamental to the study of quantum cryptography, not only because of its own importance, but also because it provides a testbed for new techniques that can be later applied to related problems (for example, quantum computation verification). Known protocols on this problem are mainly either information-theoretically (IT) secure or based on trapdoor assumptions (public key encryptions). In this paper we study how the availability of symmetric-key primitives, modeled by a random oracle, changes the complexity of universal blind quantum computation. We give a new universal blind quantum computation protocol. Similar to previous works on IT-secure protocols (for example, BFK [FOCS09, arXiv:0807.4154]), our protocol can be divided into two phases. In the first phase the client prepares some quantum gadgets with relatively simple quantum gates and sends them to the server, and in the second phase the client is entirely classical -- it does not even need quantum storage. Crucially, the protocol's first phase is succinct, that is, its complexity is independent of the circuit size. Given the security parameter $\kappa$, its complexity is only a fixed polynomial of $\kappa$, and can be used to evaluate any circuit (or several circuits) of size up to a subexponential of $\kappa$. In contrast, known schemes either require the client to perform quantum computations that scale with the size of the circuit [FOCS09, arXiv:0807.4154], or require trapdoor assumptions [Mahadev, FOCS18, arXiv:1708.02130].Comment: 231 pages, 8 figures, 1 table. Add a separate section for extended technical overview; several readability improvement

CLUSTERING DATABASE MENGGUNAKAN TEKNOLOGI DBMS

Salah satu keunggulan Oracle sebagai DBMS ( Database Management System ) adalah mampu menangani banyak sekali data yang masuk dan keluar dari database. Dengan adanya keunggulan tersebut, database Oracle digunakan oleh banyak perusahaan yang mempunyai kapasitas data yang sangat besar. Tapi, jika pada Server yang menghubungkan antara client dan database Oracle mengalami traffic yang sangat tinggi, maka akan terjadi kemacetan pada Server tersebut yang bisa membuat database menjadi down ( mati ). Hal tersebut bisa membuat perusahaan tersebut mengalami kerugian besar. Oracle mengatasi masalah tersebut dengan mengimplementasikan sebuah teknologi Clustering Database yang disebut Real Application Cluster (RAC) dimana pengaksesan database Oracle dibagi menjadi beberapa server dengan tujuan server - server tersebut mampu mengatasi masalah traffic yang sering terjadi apabila banyak sekali client yang mengakses ke database. Kata kunci : RAC, oracle, database