{"id":594,"date":"2022-08-06T18:35:59","date_gmt":"2022-08-06T10:35:59","guid":{"rendered":"https:\/\/www.lcettsg.cn\/code\/?p=594"},"modified":"2022-08-06T18:35:59","modified_gmt":"2022-08-06T10:35:59","slug":"%e4%bb%80%e4%b9%88%e6%98%afhash%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"https:\/\/www.lcettsg.cn\/code\/?p=594","title":{"rendered":"\u4ec0\u4e48\u662fhash\u51fd\u6570"},"content":{"rendered":"\n<p>\u54c8\u5e0c\u51fd\u6570\uff08Hash Function\uff09\uff0c\u4e5f\u79f0\u4e3a\u6563\u5217\u51fd\u6570\uff0c\u7ed9\u5b9a\u4e00\u4e2a\u8f93\u5165x\uff0c\u5b83\u4f1a\u7b97\u51fa\u76f8\u5e94\u7684\u8f93\u51faH(x)\u3002\u54c8\u5e0c\u51fd\u6570\u7684\u4e3b\u8981\u7279\u5f81\u662f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u8f93\u5165x\u53ef\u4ee5\u662f\u4efb\u610f\u957f\u5ea6\u7684\u5b57\u7b26\u4e32<\/li><li>\u8f93\u51fa\u7ed3\u679c\u5373H(x)\u7684\u957f\u5ea6\u662f\u56fa\u5b9a\u7684<\/li><li>\u8ba1\u7b97 H(x) \u7684\u8fc7\u7a0b\u662f\u9ad8\u6548\u7684\uff08\u5bf9\u4e8e\u957f\u5ea6\u4e3a n \u7684\u5b57\u7b26\u4e32 x \uff0c\u8ba1\u7b97\u51fa H(x) \u7684\u65f6\u95f4\u590d\u6742\u5ea6\u5e94\u4e3a O(n) \uff09<\/li><\/ul>\n\n\n\n<p>\u53e6\u5916\u54c8\u5e0c\u51fd\u6570\u4e00\u822c\u8fd8\u8981\u6c42\u4ee5\u4e0b\u4e24\u79cd\u7279\u70b9\uff1a<\/p>\n\n\n\n<p><strong>1<\/strong><strong>\u3001\u514d\u78b0\u649e<\/strong>\uff1a\u5373\u4e0d\u4f1a\u51fa\u73b0\u8f93\u5165 x\u2260y \uff0c\u4f46\u662fH(x)=H(y) \u7684\u60c5\u51b5\uff0c\u5176\u5b9e\u8fd9\u4e2a\u7279\u70b9\u5728\u7406\u8bba\u4e0a\u5e76\u4e0d\u6210\u7acb\uff0c\u6bd4\u5982\u76ee\u524d\u6bd4\u7279\u5e01\u4f7f\u7528\u7684 SHA256 \u7b97\u6cd5\uff0c\u4f1a\u6709 2^256 \u79cd\u8f93\u51fa\uff0c\u5982\u679c\u6211\u4eec\u8fdb\u884c 2^256 + 1 \u6b21\u8f93\u5165\uff0c\u90a3\u4e48\u5fc5\u7136\u4f1a\u4ea7\u751f\u4e00\u6b21\u78b0\u649e\uff0c\u4e8b\u5b9e\u4e0a\uff0c\u901a\u8fc7&nbsp;<a href=\"https:\/\/link.jianshu.com\/?t=https%3A%2F%2Fcrypto.stackexchange.com%2Fquestions%2F39641%2Fwhat-are-the-odds-of-collisions-for-a-hash-function-with-256-bit-output\" target=\"_blank\" rel=\"noreferrer noopener\">\u7406\u8bba\u8bc1\u660e<\/a>&nbsp;\uff0c\u901a\u8fc7 2^130 \u6b21\u8f93\u5165\u5c31\u4f1a\u670999%\u7684\u53ef\u80fd\u6027\u53d1\u751f\u4e00\u6b21\u78b0\u649e\uff0c\u4e0d\u8fc7\u5373\u4f7f\u5982\u6b64\uff0c\u5373\u4fbf\u662f\u4eba\u7c7b\u5236\u9020\u7684\u6240\u6709\u8ba1\u7b97\u673a\u81ea\u5b87\u5b99\u8bde\u751f\u5f00\u59cb\u4e00\u76f4\u8fd0\u7b97\u5230\u4eca\u5929\uff0c\u53d1\u751f\u4e00\u6b21\u78b0\u649e\u7684\u51e0\u7387\u4e5f\u662f\u6781\u5176\u5fae\u5c0f\u7684\u3002<\/p>\n\n\n\n<p><strong>2<\/strong><strong>\u3001\u9690\u533f\u6027<\/strong>\uff1a\u4e5f\u5c31\u662f\u8bf4\uff0c\u5bf9\u4e8e\u4e00\u4e2a\u7ed9\u5b9a\u7684\u8f93\u51fa\u7ed3\u679c H(x) \uff0c\u60f3\u8981\u9006\u63a8\u51fa\u8f93\u5165 x \uff0c\u5728\u8ba1\u7b97\u4e0a\u662f\u4e0d\u53ef\u80fd\u7684\u3002\u5982\u679c\u60f3\u8981\u5f97\u5230 H(x) \u7684\u53ef\u80fd\u7684\u539f\u8f93\u5165\uff0c\u4e0d\u5b58\u5728\u6bd4\u7a77\u4e3e\u66f4\u597d\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p>hash \u7b97\u6cd5\u7684\u539f\u7406\u662f\u8bd5\u56fe\u5c06\u4e00\u4e2a\u7a7a\u95f4\u7684\u6570\u636e\u96c6\u6620\u5c04\u5230\u53e6\u5916\u4e00\u4e2a\u7a7a\u95f4\uff08\u901a\u5e38\u6bd4\u539f\u7a7a\u95f4\u8981\u5c0f\uff09\uff0c\u5e76\u5229\u7528\u8d28\u6570\u5c06\u6570\u636e\u96c6\u80fd\u591f\u5747\u5300\u7684\u6620\u5c04\u3002\u76ee\u524d\u4e3b\u6d41\u7684 hash \u7b97\u6cd5\u6709\uff1a<strong>md4<\/strong>\u3001<strong>md5<\/strong>\u3001<strong>sha\u7cfb\u5217<\/strong>\u3002<\/p>\n\n\n\n<p><strong>MD4<\/strong><\/p>\n\n\n\n<p>MD4\u662f\u9ebb\u7701\u7406\u5de5\u5b66\u9662\u6559\u6388 Ronald Rivest \u4e8e1990\u5e74\u8bbe\u8ba1\u51fa\u6765\u7684\u7b97\u6cd5\u3002\u5176\u6458\u8981\u957f\u5ea6\u4e3a128\u4f4d\uff0c\u4e00\u822c\u752832\u4f4d\u7684\u5341\u516d\u8fdb\u5236\u6765\u8868\u793a\u3002<\/p>\n\n\n\n<p>2004\u5e748\u6708\u6e05\u534e\u5927\u5b66\u6559\u6388\u738b\u5c0f\u4e91\uff0c\u6307\u51fa\u5728\u8ba1\u7b97MD4\u65f6\u53ef\u80fd\u53d1\u751f\u6742\u51d1\u51b2\u649e\u3002\u4e0d\u4e45\u4e4b\u540e\uff0cDobbertin \u7b49\u4eba\u53d1\u73b0\u4e86MD4\u5728\u8ba1\u7b97\u8fc7\u7a0b\u4e2d\u7b2c\u4e00\u6b65\u548c\u7b2c\u4e09\u6b65\u4e2d\u7684\u6f0f\u6d1e\uff0c\u5e76\u5411\u5927\u5bb6\u6f14\u793a\u4e86\u5982\u4f55\u5229\u7528\u4e00\u90e8\u666e\u901a\u7535\u8111\u5728\u51e0\u5206\u949f\u5185\u627e\u5230MD4\u4e2d\u7684\u51b2\u7a81\uff0c\u6beb\u65e0\u7591\u95ee\uff0cMD4\u5c31\u6b64\u88ab\u6dd8\u6c70\u6389\u4e86\u3002<\/p>\n\n\n\n<p><strong>MD5<\/strong><\/p>\n\n\n\n<p>1991\u5e74\uff0cRivest \u5f00\u53d1\u51fa\u6280\u672f\u4e0a\u66f4\u4e3a\u8d8b\u8fd1\u6210\u719f\u7684MD5\u7b97\u6cd5\uff0c\u5b83\u5728MD4\u7684\u57fa\u7840\u4e0a\u589e\u52a0\u4e86&#8221;\u5b89\u5168-\u5e26\u5b50&#8221;\uff08safety-belts\uff09\u7684\u6982\u5ff5\u3002\u867d\u7136 MD5 \u6bd4 MD4 \u590d\u6742\u5ea6\u5927\u4e00\u4e9b\uff0c\u4f46\u5374\u66f4\u4e3a\u5b89\u5168\u3002\u8fd9\u4e2a\u7b97\u6cd5\u5f88\u660e\u663e\u7684\u7531\u56db\u4e2a\u548c MD4 \u8bbe\u8ba1\u6709\u5c11\u8bb8\u4e0d\u540c\u7684\u6b65\u9aa4\u7ec4\u6210\u3002<\/p>\n\n\n\n<p>MD5 \u62e5\u6709\u5f88\u597d\u7684\u6297\u4fee\u6539\u6027\uff0c\u5373\u5bf9\u539f\u6570\u636e\u8fdb\u884c\u4efb\u4f55\u6539\u52a8\uff0c\u54ea\u6015\u53ea\u4fee\u65391\u4e2a\u5b57\u8282\uff0c\u6240\u5f97\u5230\u7684MD5\u503c\u90fd\u6709\u5f88\u5927\u533a\u522b\u3002<\/p>\n\n\n\n<p>MD5\u5f88\u597d\u7684\u7528\u5728\u4e86\u5927\u6587\u4ef6\u7684\u65ad\u70b9\u7eed\u4f20\u4e0a\uff1a\u5982\u679c\u6709\u4e00\u4e2a 5MB \u7684\u6587\u4ef6 \u5ba2\u6237\u7aef\u628a\u5b83\u5206\u5272\u62105\u7247 1MB \u7684\u6587\u4ef6 \u5728\u4e0a\u4f20\u7684\u65f6\u5019\u4e0a\u4f20\u4e24\u4e2a MD5 \u503c\uff0c\u4e00\u4e2a\u662f\u5f53\u524d\u4e0a\u4f20\u7684\u6587\u4ef6\u7247\u7684 MD5 \u8fd8\u6709\u4e00\u4e2a\u5c31\u662f\u62fc\u63a5\u4e4b\u540e\u7684 MD5 (\u5982\u679c\u73b0\u5728\u4e0a\u4f20\u7684\u662f\u7b2c\u4e8c\u7247 \u8fd9\u4e2aMD5\u5c31\u5e94\u8be5\u662f\u7b2c\u4e00\u7247\u52a0\u4e0a\u7b2c\u4e8c\u7247\u7684MD5)\uff0c \u901a\u8fc7\u8fd9\u6837\u7684\u65b9\u5f0f\u80fd\u4fdd\u8bc1\u6587\u4ef6\u7684\u5b8c\u6574\u6027\u3002<\/p>\n\n\n\n<p>\u5f53\u5982\u679c\u6587\u4ef6\u4f20\u5230\u4e00\u534a\u65ad\u4e86\uff0c\u670d\u52a1\u5668\u53ef\u4ee5\u901a\u8fc7\u9a8c\u8bc1\u6587\u4ef6 MD5 \u503c\u5c31\u53ef\u4ee5\u5f97\u77e5\u7528\u6237\u5df2\u7ecf\u4f20\u5230\u4e86\u7b2c\u51e0\u7247\uff0c\u5e76\u4e14\u77e5\u9053\u4e4b\u524d\u4e0a\u4f20\u7684\u6587\u4ef6\u6709\u6ca1\u6709\u53d1\u751f\u53d8\u5316\uff0c\u5c31\u53ef\u4ee5\u5224\u65ad\u51fa\u7528\u6237\u9700\u8981\u4ece\u7b2c\u51e0\u7247\u5f00\u59cb\u4f20\u9012\u3002<\/p>\n\n\n\n<p>\u4e0d\u8fc7\u57282004\u5e748\u6708\u7684\u56fd\u9645\u5bc6\u7801\u5b66\u4f1a\u8bae\uff08Crypto\u20192004\uff09\uff0c\u738b\u5c0f\u4e91\u63d0\u51fa\u4e86\u4e00\u79cd\u5feb\u901f\u627e\u5230 MD5 \u78b0\u649e\u7684\u65b9\u6cd5\uff08\u53c2\u89c1\u5176<a href=\"https:\/\/link.jianshu.com\/?t=http%3A%2F%2Fmerlot.usc.edu%2Fcsac-f06%2Fpapers%2FWang05a.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">\u8bba\u6587<\/a>\uff09\uff0c\u964d\u4f4e\u4e86 MD5 \u7684\u5b89\u5168\u6027\uff0c\u4eba\u4eec\u5f00\u59cb\u5bfb\u6c42\u66f4\u52a0\u53ef\u9760\u7684\u52a0\u5bc6\u7b97\u6cd5\u3002<\/p>\n\n\n\n<p><strong>SHA<\/strong><strong>\u7cfb\u5217<\/strong><\/p>\n\n\n\n<p>SHA\u7684\u5168\u79f0\u662fSecure Hash Algorithm(\u5b89\u5168hash\u7b97\u6cd5)\uff0cSHA\u7cfb\u5217\u6709\u4e94\u4e2a\u7b97\u6cd5\uff0c\u5206\u522b\u662f SHA-1\u3001SHA-224\u3001SHA-256\u3001SHA-384\uff0c\u548cSHA-512\uff0c\u7531\u7f8e\u56fd\u56fd\u5bb6\u5b89\u5168\u5c40\uff08NSA\uff09\u6240\u8bbe\u8ba1\uff0c\u5e76\u7531\u7f8e\u56fd\u56fd\u5bb6\u6807\u51c6\u4e0e\u6280\u672f\u7814\u7a76\u9662\uff08NIST\uff09\u53d1\u5e03\uff0c\u662f\u7f8e\u56fd\u7684\u653f\u5e9c\u6807\u51c6\u3002\u540e\u56db\u8005\u6709\u65f6\u5e76\u79f0\u4e3a SHA-2\u3002SHA-1\u5728\u8bb8\u591a\u5b89\u5168\u534f\u5b9a\u4e2d\u5e7f\u4e3a\u4f7f\u7528\uff0c\u5305\u62ec TLS\/SSL \u7b49\uff0c\u662f MD5 \u7684\u540e\u7ee7\u8005\u3002<\/p>\n\n\n\n<p><strong>SHA-1<\/strong><\/p>\n\n\n\n<p>\u6700\u521d\u8be5\u7b97\u6cd5\u4e8e1993\u5e74\u53d1\u5e03\uff0c\u79f0\u505a\u5b89\u5168\u6563\u5217\u6807\u51c6 (Secure Hash Standard)\uff0c\u6700\u521d\u8fd9\u4e2a\u7248\u672c\u88ab\u79f0\u4e3a&#8221;SHA-0&#8243;\uff0c\u5b83\u5728\u53d1\u5e03\u4e4b\u540e\u5f88\u5feb\u5c31\u88abNSA\u64a4\u56de\uff0c\u56e0\u4e3a\u6709\u5f88\u5927\u7684\u5b89\u5168\u7f3a\u9677\uff0c\u4e4b\u540e\u57281995\u5e74\u53d1\u5e03\u4e86\u4fee\u8ba2\u7248\u672c\uff0c\u4e5f\u5c31\u662fSHA-1\u3002<\/p>\n\n\n\n<p>SHA-0 \u548c SHA-1 \u4f1a\u4ece\u4e00\u4e2a\u6700\u5927 2^64 \u4f4d\u5143\u7684\u8baf\u606f\u4e2d\u4ea7\u751f\u4e00\u4e32 160 \u4f4d\u5143\u7684\u6458\u8981\uff0c\u7136\u540e\u4ee5 MD4 \u53ca MD5 \u7b97\u6cd5\u7c7b\u4f3c\u7684\u539f\u7406\u6765\u52a0\u5bc6\u3002<\/p>\n\n\n\n<p>2017\u5e74\uff0c\u8c37\u6b4c\u53d1\u5e03\u4e86\u6700\u65b0\u7684\u7814\u7a76\u6210\u529f\uff0c\u5ba3\u5e03\u653b\u7834\u4e86SHA-1\uff0c\u5e76\u8be6\u7ec6\u63cf\u8ff0\u4e86\u6210\u529f\u7684SHA1\u78b0\u649e\u653b\u51fb\u65b9\u5f0f\uff0c\u4f7f\u7528\u8fd9\u79cd\u65b9\u5f0f\uff0c\u53ef\u4ee5\u5728\u4e9a\u9a6c\u900a\u7684\u4e91\u8ba1\u7b97\u5e73\u53f0\u4e0a\uff0c\u8017\u65f610\u5929\u5de6\u53f3\u521b\u5efa\u51faSHA-1\u78b0\u649e\uff0c\u5e76\u4e14\u6210\u672c\u53ef\u4ee5\u63a7\u5236\u572811\u4e07\u7f8e\u5143\u4ee5\u5185\u3002<\/p>\n\n\n\n<p>\u5373\u4f7f\u5982\u6b64\uff0c\u5bf9\u4e8e\u5355\u53f0\u673a\u5668\u6765\u8bf4\u653b\u51fb\u7684\u6210\u672c\u4f9d\u7136\u5f88\u9ad8\uff0c\u53d1\u751f\u4e00\u6b21SHA-1\u78b0\u649e\u9700\u8981\u8d85\u8fc79,223,372,036,854,775,808\u4e2aSHA1\u8ba1\u7b97\uff0c\u8fd9\u9700\u8981\u4f7f\u7528\u4f60\u7684\u673a\u5668\u8fdb\u884c6500\u5e74\u8ba1\u7b97\u3002<\/p>\n\n\n\n<p><strong>SHA2<\/strong><\/p>\n\n\n\n<p>SHA2\u5305\u62ec\u4e86SHA-224\u3001SHA-256\u3001SHA-384\uff0c\u548cSHA-512\uff0c\u8fd9\u51e0\u4e2a\u51fd\u6570\u90fd\u5c06\u8baf\u606f\u5bf9\u5e94\u5230\u66f4\u957f\u7684\u8baf\u606f\u6458\u8981\uff0c\u4ee5\u5b83\u4eec\u7684\u6458\u8981\u957f\u5ea6\uff08\u4ee5\u4f4d\u5143\u8ba1\u7b97\uff09\u52a0\u5728\u539f\u540d\u540e\u9762\u6765\u547d\u540d\uff0c\u4e5f\u5c31\u662f\u8bf4SHA-256\u4f1a\u4ea7\u751f256\u4f4d\u957f\u5ea6\u6458\u8981\u3002<\/p>\n\n\n\n<p>SHA-2\u76f8\u5bf9\u6765\u8bf4\u662f\u5b89\u5168\u7684\uff0c\u81f3\u4eca\u5c1a\u672a\u51fa\u73b0\u5bf9SHA-2\u6709\u6548\u7684\u653b\u51fb\uff01<\/p>\n\n\n\n<p>\u7531\u4e8e\u76ee\u524d\u5927\u91cf\u7684\u7f51\u7ad9\u4f7f\u7528\u7684SSL\u6570\u5b57\u8bc1\u6570\u90fd\u662f\u4f7f\u7528SHA-1\u7b7e\u540d\u7684\uff0c\u800cSHA-1\u53c8\u5df2\u7ecf\u4e0d\u5b89\u5168\uff0c\u5404\u5927\u6d4f\u89c8\u5668\u5382\u5546\u5747\u5ba3\u5e03\u4e86\u5f03\u7528SHA-1\u7684\u65f6\u95f4\u8868\uff1a<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u54c8\u5e0c\u51fd\u6570\uff08Hash Function\uff09\uff0c\u4e5f\u79f0\u4e3a\u6563\u5217\u51fd\u6570\uff0c\u7ed9\u5b9a\u4e00\u4e2a\u8f93\u5165x\uff0c\u5b83\u4f1a\u7b97\u51fa\u76f8\u5e94\u7684\u8f93\u51faH(x)\u3002\u54c8\u5e0c\u51fd\u6570\u7684 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-594","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts\/594"}],"collection":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=594"}],"version-history":[{"count":1,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts\/594\/revisions"}],"predecessor-version":[{"id":595,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts\/594\/revisions\/595"}],"wp:attachment":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=594"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=594"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}