{"id":215,"date":"2025-07-23T00:11:45","date_gmt":"2025-07-22T17:11:45","guid":{"rendered":"https:\/\/algebra.math-ugm.id\/?p=215"},"modified":"2025-07-28T10:49:06","modified_gmt":"2025-07-28T03:49:06","slug":"7th-day-cimpa-school-2025-on-arithmetic-in-action-number-theory-and-its-applications-to-cryptography-and-coding-theory","status":"publish","type":"post","link":"https:\/\/algebra.math-ugm.id\/en\/7th-day-cimpa-school-2025-on-arithmetic-in-action-number-theory-and-its-applications-to-cryptography-and-coding-theory\/","title":{"rendered":"7th Day: CIMPA SCHOOL 2025 on Arithmetic in Action: Number Theory and its Applications to Cryptography and Coding Theory"},"content":{"rendered":"<p><\/p>\n<p style=\"text-align: justify;\"><strong><span style=\"font-size: 14pt;\">Universitas Gadjah Mada, Yogyakarta, Indonesia<\/span><\/strong><\/p>\n<p style=\"text-align: justify;\"><strong><span style=\"font-size: 14pt;\">July 22, 2025<\/span><\/strong><\/p>\n<h4 style=\"text-align: justify;\" data-start=\"312\" data-end=\"338\"><span style=\"font-size: 14pt;\"><strong data-start=\"317\" data-end=\"338\">Lecturing Session<\/strong><\/span><\/h4>\n<p style=\"text-align: justify;\" data-start=\"340\" data-end=\"959\">The seventh day of CIMPA SCHOOL 2025 began with Dr. Elisa Lorenzo Garcia delivering her first lecture on <em data-start=\"449\" data-end=\"464\">Coding Theory<\/em>. She began with examples highlighting the daily need for coding theory, using parity checks and Hamming codes as motivating cases before introducing the general definitions of codes, codewords, code size, [n,k]-codes, and information rate. Dr. Garcia continued by defining the Hamming distance, discussed theoretical aspects of error correction, and presented the Singleton bound. She concluded the lecture by introducing the concept of a generator matrix of a code.<\/p>\n<p style=\"text-align: justify;\" data-start=\"961\" data-end=\"1294\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-219 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.04-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.04-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.04-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.04-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.04.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p style=\"text-align: justify;\" data-start=\"961\" data-end=\"1294\">The next session was led by Prof. Michel Waldschmidt, who continued his lecture on <em data-start=\"1048\" data-end=\"1058\">Lattices<\/em>. He began by proving the equivalence of the two definitions of lattices presented in his previous lecture and introduced th<span style=\"font-size: 1rem;\">e notion of quadratic forms, which led to a third definition of lattices using finitely generated subgroups.<\/span><\/p>\n<p style=\"text-align: justify;\" data-start=\"961\" data-end=\"1294\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-218 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.07-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.07-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.07-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.07-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.07.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p style=\"text-align: justify;\" data-start=\"1296\" data-end=\"1784\">The last lecture of the day was delivered by Dr. Adeline Roux-Langlois, providing an <em data-start=\"1385\" data-end=\"1429\">Introduction to Lattice-Based Cryptography<\/em>. She discussed various hard problems in cryptography and introduced the Shortest Vector Problem (SVP), the approximate SVP, short integer solutions, and reduction methods. Dr. Roux-Langlois concluded her lecture by defining hash functions and explaining their applications in solving short integer solutions within cryptographic contexts.<\/p>\n<p style=\"text-align: justify;\" data-start=\"1296\" data-end=\"1784\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-217 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.09-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.09-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.09-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.09-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.09.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<h4 style=\"text-align: justify;\" data-start=\"1791\" data-end=\"1816\"><span style=\"font-size: 14pt;\"><strong data-start=\"1796\" data-end=\"1816\">SageMath Session<\/strong><\/span><\/h4>\n<p style=\"text-align: justify;\" data-start=\"1818\" data-end=\"2059\">Participants engaged in hands-on SageMath activities, applying their learning by working with cryptographic algorithms such as the Caesar cipher, Vigen\u00e8re cipher, and RSA, reinforcing practical skills alongside theoretical knowledge.<\/p>\n<h4 style=\"text-align: justify;\" data-start=\"2066\" data-end=\"2093\"><span style=\"font-size: 14pt;\"><strong data-start=\"2071\" data-end=\"2093\">Extra Session<\/strong><\/span><\/h4>\n<p style=\"text-align: justify;\" data-start=\"2095\" data-end=\"2308\">The day concluded with participant presentations on their research, focusing on topics related to lattices and cryptography, allowing them to share progress and receive feedback from peers and instructors.<\/p>\n<p style=\"text-align: justify;\" data-start=\"2095\" data-end=\"2308\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-216 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.11-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.11-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.11-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.11-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-23-00.08.11.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>Universitas Gadjah Mada, Yogyakarta, Indonesia July 22, 2025 Lecturing Session [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-215","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/215","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/comments?post=215"}],"version-history":[{"count":2,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/215\/revisions"}],"predecessor-version":[{"id":250,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/215\/revisions\/250"}],"wp:attachment":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/media?parent=215"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/categories?post=215"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/tags?post=215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}