【正文】
?計(jì)算安全( putational security ) 在有限的計(jì)算資源條件下,密文不能破解。 K in K : P C ?及唯一逆算法: P = EK1。 O/S Testing, Evaluation, Certification ?H/W TCB, Tamperproof, Encryption 安全威脅 Security Threats ?threats can e from a range of sources ?various surveys, with results of order: ?55% human error ?10% disgruntled employees ?10% dishonest employees ?10% outsider access ?also have acts of god (fire, flood etc) security attacks ?偵聽 (interception) – 中途竊聽 ,攻擊機(jī)密性 ?服務(wù)中斷 (interruption) – 攻擊可用性 ?信息篡改( modification of info) 攻擊完整性 ?消息偽造( fabrication of info) 攻擊認(rèn)證性( attacks authentication ) Passive vs Active Attacks ?確定關(guān)鍵對(duì)象 (資產(chǎn) ) ?評(píng)估所面臨的威脅 ?確立合適的對(duì)策 ?執(zhí)行實(shí)施對(duì)策 ?密碼學(xué) —關(guān)鍵的技術(shù)之一 通信 ? 通信(續(xù))