セキュリティの原則

　Application Architecture for .NETの「Security, Operational Management, and Communications Policies」にシステム開発におけるセキュリティの一般原則がまとめられています。それによると、

• Whenever possible, you should rely on tested and proven security systems rather than building your own custom solution. Use industry-proven algorithms, techniques, platform-supplied infrastructure, and vendor-tested and supported technologies. If you decide to do custom development of security infrastructure, validate your approach and techniques with expert auditing and security review organizations before and after implementing it.
  
  実証されたセキュリティ機構を利用し、独自のセキュリティ機構を実装するのは避けよ
• Never trust external input. You should validate all data that is entered by users or submitted by other services.
  
  外部からの入力は信用するな
• Assume that external systems are insecure. If your application receives unencrypted sensitive data from an external system, assume that the information is compromised.
  
  外部サービスは安全でないと思え
• Apply the principle of least privilege. Don't enable more attributes on service accounts than those minimally needed by the application. Access resources with accounts that have the minimal permissions required.~
  最小特権の原則を守れ。つまり、システム上のおのおのの処理に対しては、実行に必要な最低限の特権だけを与えるべきである
• Reduce surface area. Risk will increase with the number of components and data you have exposed through the application, so you should expose only the functionality that you expect others to use.
  
  システムの境界面を減らせ
• Default to a secure mode. Don't enable services, account rights, and technologies that you don't explicitly need. When you deploy the application on client and/or server computers, its default configuration should be secure.
  
  何も設定しない場合はデフォルトで安全な動作をするようにしろ
• Follow STRIDE principles—STRIDE stands for Spoofing, Tampering, Repudiability, Information disclosure, Denial of service, and Elevation of privileges. These are classes of security vulnerabilities a system has to protect itself against.
  
  STRIDE脅威モデルに従え。
  
  ※STRIDE : なりすまし（Spoofing Identity）、データの改ざん（Tampering with Data）、否認（Repudiability）、情報の暴露（Information Disclosure）、サービス拒否（Denial of Service）、特権の昇格（Elevation of Privilege）の頭文字を取ったもの。

　なるほどね。言われりゃ当然の事だけど、ちゃんと実践しましょうってことですね。