{"id":221,"date":"2025-07-26T16:40:33","date_gmt":"2025-07-26T09:40:33","guid":{"rendered":"https:\/\/algebra.math-ugm.id\/?p=221"},"modified":"2025-07-28T10:56:41","modified_gmt":"2025-07-28T03:56:41","slug":"8th-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\/8th-day-cimpa-school-2025-on-arithmetic-in-action-number-theory-and-its-applications-to-cryptography-and-coding-theory\/","title":{"rendered":"8th Day: CIMPA SCHOOL 2025 on Arithmetic in Action: Number Theory and its Applications to Cryptography and Coding Theory"},"content":{"rendered":"<p><span style=\"font-size: 14pt;\"><strong>Universitas Gadjah Mada, Yogyakarta, Indonesia<\/strong><\/span><\/p>\n<p><span style=\"font-size: 14pt;\"><strong>July 23, 2025<\/strong><\/span><\/p>\n<p><span style=\"font-size: 14pt;\"><strong style=\"text-align: justify;\">Lecturing Session:<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\">The 8th day of CIMPA SCHOOL 2025 began with a lecture by Prof. Indah Emilia Wijayanti on Cryptography. She opened the session by introducing the concept of cryptographic systems and the discrete logarithm problem. The lecture continued with a detailed explanation of the ElGamal Cryptosystem, supported by clear examples. Prof. Indah then presented the Weil pairing on elliptic curves, discussing its fundamental properties and computations. She introduced several key exchange protocols, including the Elliptic Curve Diffie-Hellman Key Exchange, standard Diffie-Hellman Key Exchange, Tripartite Diffie-Hellman Key Exchange, and Bilinear Diffie-Hellman Key Exchange. The lecture concluded with an illustration of how the ElGamal Cryptosystem operates on elliptic curves.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-244 size-large\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/DSC00198-1024x576.jpg\" alt=\"\" width=\"640\" height=\"360\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/DSC00198-1024x576.jpg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/DSC00198-300x169.jpg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/DSC00198-768x432.jpg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/DSC00198-1536x864.jpg 1536w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/DSC00198-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-222 size-large\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.58-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.58-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.58-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.58-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.58.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p>The next session was delivered by Dr. Anna Maria Iezzi, focusing on Coding Theory. She began with Reed\u2013Solomon codes and their construction before moving on to cyclic codes. Dr. Iezzi explained essential properties such as the number of divisors, code dimension, and generator matrices. She highlighted the bijection between cyclic codes and ideals in the quotient ring of a polynomial ring. The session ended with examples that reinforced the theoretical concepts.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-223 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.59-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.59-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.59-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.59-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-26-16.37.59.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p style=\"text-align: justify;\"><strong><span style=\"font-size: 14pt;\">Exercise Session: <\/span><\/strong><\/p>\n<p style=\"text-align: justify;\">The day concluded with an exercise session, during which participants continued their work on cryptography problems. The atmosphere remained productive and interactive, supported by the speaker team.<\/p>\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>Universitas Gadjah Mada, Yogyakarta, Indonesia July 23, 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-221","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/221","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=221"}],"version-history":[{"count":4,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/221\/revisions"}],"predecessor-version":[{"id":259,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/221\/revisions\/259"}],"wp:attachment":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/media?parent=221"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/categories?post=221"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/tags?post=221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}