{"id":67,"date":"2024-03-25T20:25:28","date_gmt":"2024-03-25T20:25:28","guid":{"rendered":"https:\/\/ribaldoneelia.com\/?p=67"},"modified":"2024-11-15T12:35:23","modified_gmt":"2024-11-15T12:35:23","slug":"asymmetric-cryptography","status":"publish","type":"post","link":"https:\/\/ribaldoneelia.com\/index.php\/2024\/03\/25\/asymmetric-cryptography\/","title":{"rendered":"Asymmetric Cryptography"},"content":{"rendered":"\n

The Asymmetric cryptography use two key, one to encrypt message and one to decrypt it. The Public Key<\/strong><\/em> is used to encrypt <\/strong>the message while the Private Key<\/em><\/strong> to decrypt<\/strong> the encrypted message. This two keys are generated using RSA cryptosystem, for example using python you can generate the keys in this way:<\/p>\n\n\n\n

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import<\/span> rsa<\/span><\/span>\n<\/span>\npublic_key, private_key <\/span>=<\/span> rsa.<\/span>newkeys<\/span>(<\/span>1024<\/span>)  <\/span># 1024 bits<\/span><\/span>\n<\/span>\nprint<\/span>(private_key.<\/span>save_pkcs1<\/span>(<\/span>"PEM"<\/span>))<\/span><\/span>\n"""The print return something like:<\/span><\/span>\nb'-----BEGIN RSA PRIVATE KEY-----<\/span><\/span>\nMIICYAIBAAKBgQCMmErj1wy8cr0dPffEviqxcWbsGPp+hrLlIxc3P8bOj3q53fWX<\/span><\/span>\n3dm+sp6gOsJl9Ca+qd3uonuci0kvpqhRvAh1yFbFwYulqcNy1niI9v05PHfLOKam<\/span><\/span>\nvcwMViynk9G2xphKCdqA3sexyToDJrDbMBBgntjraxf1eumxweUf9wDHeQIDAQAB<\/span><\/span>\nAoGATMQ63\/zj72GW8QiM6NgM56ZL1E4vODbEJ2jpnDkujEq7cBFJsApqgj11b3el<\/span><\/span>\n\/ZU6MpD9pPcDF47V\/za4CLmOAjbspVZOECciwmxJueNJnBkN8YtiOHhuH1gwLnSi<\/span><\/span>\n13NRGJ+k7tzaqXcfC4XCu5DOCnWupZkVTy6TH4BhgOdYEqECRQCh9nnsu7LizjeX<\/span><\/span>\nWVaAQvRvh6IrJ2D0J4abejsN4F+IXuDmtjvRr7ms0t8TFHpucmhyzuYHgNwhepKe<\/span><\/span>\nc2Bca0NULcCd3wI9AN45xgRffv9GuiIdAD336KKQMhA5E\/6jNQu9a1tMGzCxPIuS<\/span><\/span>\ngLh3FKyrUOZj2aTp7y8IIrSOt6Iv\/mmVpwJFAISiGMTCDUNpRuMdmRXePthaxXX7<\/span><\/span>\ngI1RFQ2b8mJxvSorMJge4ivccPxTj7TLT1vFOz3Rq1S3tQ2BmDJEH8RvXqq\/8P4X<\/span><\/span>\nAjxpnjPK6EhHs6nLhNUUnrrmaHoi0735DECt770Siz1xCwunml2rTo1484NjvJk4<\/span><\/span>\nlCalx8wW3K3SW9UjAYkCRCyrHE6CPXUvNwEfr+XvcF4T9A\/BuxUg8R9DSLy7TbQs<\/span><\/span>\nrvNEwm5defUV7kgHerQdpfezSJ++kIYXl0egFW31wcYYVbIl<\/span><\/span>\n-----END RSA PRIVATE KEY-----'<\/span><\/span>\n"""<\/span><\/span>\n<\/span>\nprint<\/span>(public_key.<\/span>save_pkcs1<\/span>(<\/span>"PEM"<\/span>))<\/span><\/span>\n"""<\/span><\/span>\nb'-----BEGIN RSA PUBLIC KEY-----<\/span><\/span>\nMIGJAoGBAIyYSuPXDLxyvR0998S+KrFxZuwY+n6GsuUjFzc\/xs6Pernd9Zfd2b6y<\/span><\/span>\nnqA6wmX0Jr6p3e6ie5yLSS+mqFG8CHXIVsXBi6Wpw3LWeIj2\/Tk8d8s4pqa9zAxW<\/span><\/span>\nLKeT0bbGmEoJ2oDex7HJOgMmsNswEGCe2OtrF\/V66bHB5R\/3AMd5AgMBAAE=<\/span><\/span>\n-----END RSA PUBLIC KEY-----'<\/span><\/span>\n"""<\/span><\/span><\/code><\/pre><\/div>\n<\/div><\/div>\n\n\n\n
I love python! Anyway be aware of use rsa package, indeed in the help of the package is written:<\/p>\n\n\n\n
“WARNING: this implementation does not use compression of the cleartext input to prevent repetitions, or other common security improvements. Use with care.”<\/em><\/p>\n\n\n\n
Encrypt and Decrypt<\/h3>\n\n\n\n
Suppose to be a spy manager, you have many spies around the world. In order to receive reports from your spy you can share the public key public_key<\/strong><\/em>  in a whatever way (like above).<\/p>\n\n\n\n
So for example James Bond every day check a specific log site where you place the public key, he copy the key and he run these python code:<\/p>\n\n\n\n
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jb_report <\/span>=<\/span> <\/span>"""Hello, I'm James Bond, I've found a suspicious activity here, the destiny of the Humans is in my hands."""<\/span><\/span>\njb_report_enc <\/span>=<\/span> rsa.<\/span>encrypt<\/span>(jb_report.<\/span>encode<\/span>(), public_key)<\/span><\/span>\n# jb_report_enc will be:<\/span><\/span>\nb<\/span>'Lb^?<\/span>\\xb7\\x1e\\xa0\\xdd\\xf6<\/span>B<\/span>\\x06<\/span>U<\/span>\\x86<\/span>?<\/span>\\xe6\\x84\\x9b\\x1f\\x14<\/span>J<\/span>\\xbc\\x94<\/span>sf<\/span>\\xa1<\/span>z<\/span>\\xc8<\/span>"<\/span>\\x05<\/span>X<\/span>\\x95<\/span>c<\/span>\\xa7<\/span>p<\/span>\\xce<\/span>. <\/span>\\x7f\\xc5\\x90\\x92\\xfc\\x9e<\/span>i<\/span>\\xf6<\/span>n%<\/span>\\xe4<\/span>=S<\/span>\\x1e\\xae\\xb3<\/span>Tu<\/span>\\xba<\/span>$<\/span>\\x93<\/span>0<\/span>\\x92\\xd8<\/span>=<\/span>\\xeb\\xf8\\x12\\xac\\xb6\\xe7\\xc8<\/span>1<\/span>\\x81<\/span>)<\/span>\\x8c\\x02<\/span>U[L<<\/span>\\xd1\\x03\\xe2\\x90\\x87\\x10\\x8f\\xe7<\/span>Kh<\/span>\\xcb<\/span>?Mn(<\/span>\\xea\\xad<\/span>n<\/span>\\xa9<\/span>#Q<\/span>\\xd7<\/span>@<\/span>\\xa4\\x95<\/span>:<\/span>\\xd8<\/span>##<\/span>\\x8e<\/span>K<\/span>\\xde<\/span>m=K<\/span>\\xc4\\xb8<\/span>u<\/span>\\xc3\\x19\\x96<\/span>A<\/span>\\x91<\/span>.r<\/span>\\xe9\\xa9<\/span>y<\/span>\\x08\\x82<\/span>'<\/span><\/span>\n<\/span><\/code><\/pre><\/div>\n\n\n\n
 These bytes are the message that James Bond will share in the log site.<\/p>\n\n\n\n
The spy manager received that can decrypt using its own secret key in this way:<\/p>\n\n\n\n
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decoded <\/span>=<\/span> rsa.<\/span>decrypt<\/span>(jb_report_enc, private_key).<\/span>decode<\/span>()<\/span><\/span>\n# decoded data will be again:<\/span><\/span>\n"""Hello, I'm James Bond, I've found a suspicious activity here, the destiny of the Humans is in my hands."""<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
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Now you can be the next spy!<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
The Asymmetric cryptography use two key, one to encrypt message and one to decrypt it. The Public Key is used<\/p>\n
Continue readingAsymmetric Cryptography<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/posts\/67"}],"collection":[{"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/comments?post=67"}],"version-history":[{"count":8,"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/posts\/67\/revisions"}],"predecessor-version":[{"id":76,"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/posts\/67\/revisions\/76"}],"wp:attachment":[{"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/media?parent=67"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/categories?post=67"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ribaldoneelia.com\/index.php\/wp-json\/wp\/v2\/tags?post=67"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}