{"version":"https://jsonfeed.org/version/1.1","title":"苏迟但到的主页","home_page_url":"https://kexohproject.pages.dev","feed_url":"https://kexohproject.pages.dev/json/","description":"<p>你好，欢迎访问个人主页！</p><p>擅长密码学，安全分析，数字水印等技术。</p><p>你可以联系我通过:findmykexin@gmail.com或者知乎私信。</p><p>我的知乎链接：<a href=\"https://www.zhihu.com/people/su-chi-dan-dao\" rel=\"noopener noreferrer\" target=\"_blank\">苏迟但到 - 知乎 (zhihu.com)</a></p><p>我的github链接：<a href=\"https://github.com/kexinoh\" rel=\"noopener noreferrer\" target=\"_blank\">kexinoh</a></p>","icon":"https://kexohcdn.gptapi.cyou/kexohproject/production/images/channel-2e54d141ee195646ca12a9d16507a908.jpg","favicon":"https://kexohcdn.gptapi.cyou/kexohproject/production/images/favicon-340a2925d02a0386f3b954a032834917.jpg","authors":[{"name":"苏迟但到"}],"language":"zh-cn","items":[{"id":"tHUuT3kZn2-","title":"是否存在一串字符串经过MD5哈希后还是这串字符串？","content_html":"<p data-pid=\"Z9CDvSV9\">不一定存在。</p><p data-pid=\"I5DONVpZ\">hash构造中就是整体尽可能地造成雪崩效应和随机性，并不会故意把这样的数字给舍弃了。事实上，如果专门有一个这个步骤，反而对整体的扰乱效果降低了。</p><p data-pid=\"SbFNdfgf\">在二战的时候，德军每天的密码设置人员就为了加大破解难度（大误），就尽可能使得密钥不要出现昨天出现过的字母，但这个秘密被英国观测出来了之后反而加快了破解速度。</p><p data-pid=\"7iou9xbd\">但概率学上我们可以计算出来。整体计算出来的概率可以通过生日攻击来计算。一个数字随机碰到自己的概率为1/2^128,那2^128个数中存在碰到自己的概率为</p><p data-pid=\"AHQ4Kyil\">（1-1/2^128)^(2^128)=1/e=0.36787.</p>","content_text":"不一定存在。\n\nhash构造中就是整体尽可能地造成雪崩效应和随机性，并不会故意把这样的数字给舍弃了。事实上，如果专门有一个这个步骤，反而对整体的扰乱效果降低了。\n\n在二战的时候，德军每天的密码设置人员就为了加大破解难度（大误），就尽可能使得密钥不要出现昨天出现过的字母，但这个秘密被英国观测出来了之后反而加快了破解速度。\n\n但概率学上我们可以计算出来。整体计算出来的概率可以通过生日攻击来计算。一个数字随机碰到自己的概率为1/2^128,那2^128个数中存在碰到自己的概率为\n\n（1-1/2^128)^(2^128)=1/e=0.36787.","date_published":"2021-02-03T06:46:14.000Z","_microfeed":{"web_url":"https://kexohproject.pages.dev/i/md5-tHUuT3kZn2-/","json_url":"https://kexohproject.pages.dev/i/tHUuT3kZn2-/json/","rss_url":"https://kexohproject.pages.dev/i/tHUuT3kZn2-/rss/","guid":"tHUuT3kZn2-","status":"published","itunes:title":"New Article Title for iTunes","date_published_short":"Wed Feb 03 2021","date_published_ms":1612334774000}}],"_microfeed":{"microfeed_version":"0.1.2","base_url":"https://kexohproject.pages.dev","categories":[{"name":"Education","categories":[{"name":"Language Learning"}]},{"name":"Technology"}],"subscribe_methods":[{"name":"RSS","type":"rss","url":"https://kexohproject.pages.dev/rss/","image":"https://kexohproject.pages.dev/assets/brands/subscribe/rss.png","enabled":true,"editable":false,"id":"4KlfbtkEfzy"},{"name":"JSON","type":"json","url":"https://kexohproject.pages.dev/json/","image":"https://kexohproject.pages.dev/assets/brands/subscribe/json.png","enabled":true,"editable":false,"id":"DVFm7TYiNSq"}],"description_text":"你好，欢迎访问个人主页！\n\n擅长密码学，安全分析，数字水印等技术。\n\n你可以联系我通过:findmykexin@gmail.com或者知乎私信。\n\n我的知乎链接：苏迟但到 - 知乎 (zhihu.com)\n\n我的github链接：kexinoh","copyright":"©2024","itunes:type":"episodic","items_sort_order":"newest_first"}}