UNDERSTANDING THE NEW U.S. NATional SPACE POLICY，John M. Logsdon
Director, Space Policy Institute
Elliott School of InterNATional Affairs
The George Washington University
Washington, DC, USA
This document represents the first stage in a process of taking the NATional Strategy for Police Information Systems (NSPIS) forward. It defines the mechanisms to ensure that we (and our partners) have access to the right information, in the right form, in the right time at an appropriate cost. The Strategy will ensure the Police Service has a collective understanding of the value of information and that we are able to exploit NATional Information Assets in support of local policing.
SHA-1(Secure Hash Algorithm)是美國國家標準局(NATional Institute of Standard and Technology NIST)為了配合數位簽章演算法(Digital Signature Algorithm DSA)的使用所發布的聯邦資訊處理標準-FIPS PUB 180-1(Federal Information Processing Standard Publication 180-1),而SHA-1 則是SHA-1 (FIPS180)的改良版,現今與MD5 皆廣被使用拿來做密碼驗證功能.其設計的方法是根據MD4,來對輸入的資料訊息(Message)產生出一個160 位元的訊息摘要(Digest) ,對於資料安全性提供了有效的保障.
