在Enigma被发明之前,密码一直是个不太靠得住的东西。到一战结束时,所有的密码都被找到了行之有效的破解方法,连几百年来被认为坚不可破的维吉耐尔密码也被破解了,密码的攻防平衡不断向破解方倾斜。Enigma的出现改变了这个局面,这个看起来像台打字机的电子机械装置后来被证明是有史以来最为可靠的加密系统。 Before Enigma was invented, the password was always unreliable. By the end of World War I, all the passwords were found to be effective methods of cracking. Even the Viagentian password, which for centuries had been considered unbreakable, was cracked. The balance of offensive and defensive passwords kept tilting toward the cracker . The appearance of Enigma changed the situation, and the electromechanical device, which looked like a typewriter, turned out to be the most reliable encryption system ever.