?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Algoritmos+heur%C3%ADsticos+para+la+optimizaci%C3%B3n+de+Substitution+Boxes&rft.creator=Santos+Jim%C3%A9nez%2C+Emiliano&rft.contributor=Pozo+Coronado%2C+Luis&rft.contributor=Garc%C3%ADa+Pardo%2C+Eduardo&rft.subject=Computer+Science&rft.description=En+pleno+siglo+XXI%2C+la+ciberseguridad+es+ya+una+parte+importante+de+la+vida+cotidiana+de+muchos+ciudadanos.+La+protecci%C3%B3n+de+la+informaci%C3%B3n+y+la+defensa+contra+ataques%0D%0Acibern%C3%A9ticos+es+ya+algo+fundamental+y%2C+dentro+de+este+%C3%A1mbito%2C+el+cifrado+se+ha+vuelto+una+pieza+imprescindible+en+tales+tareas.+Por+ello%2C+el+desarrollo+de+nuevos+m%C3%A9todos+de+cifrado+cada+vez+es+m%C3%A1s+relevante.+Por+otro+lado%2C+la+Inteligencia+Artificial+ha+sufrido+un+auge+notorio+durante+la+%C3%BAltima+d%C3%A9cada.+Sus+t%C3%A9cnicas+ya+son+cada+vez+m%C3%A1s+empleadas+en+diferentes+contextos%2C+entre+los+que+se+encuentra+la+ciberseguridad.+Este+proyecto+aborda+la+aplicaci%C3%B3n+de+t%C3%A9cnicas+de+Inteligencia+Artificial+para+la+mejora+de+diferentes+aspectos%2C+relacionados+con+la++criptolog%C3%ADa%2C+en+el+%C3%A1mbito+de+la+ciberseguridad.+Una+S-Box+es+un+componente+importante+del+cifrado+en+bloque%2C+cuyo+objetivo+es+transformar+una+entrada+de+n+bits+en+una+salida+diferente+de+m+bits.+En+la+%C3%BAltima+d%C3%A9cada+varios%0D%0Ainvestigadores+han+intentado+descubrir+nuevas+formas+de+crear+S-Boxes.+La+aplicaci%C3%B3n+de+t%C3%A9cnicas+heur%C3%ADsticas+(t%C3%A9cnicas+pertenecientes+al+campo+de+la+Inteligencia+Artificial)+para+generar+S-Boxes+con+buenas+propiedades+criptogr%C3%A1ficas+ha+cogido+mucha+relevancia+en+relaci%C3%B3n+a+m%C3%A9todos+m%C3%A1s+convencionales.+El+enfoque+que+se+aplica+en+este+proyecto+consiste+en+adaptar+el+m%C3%A9todo+cient%C3%ADfico+para+crear+un+algoritmo+heur%C3%ADstico+que+optimice+algunas%0D%0Ade+las+propiedades+criptogr%C3%A1ficas+(m%C3%A1s+concretamente+la+no-linealidad)+de+estos+componentes+el+cifrado+en+bloque.+M%C3%A1s+concretamente%2C+la+propuesta+de+este+proyecto+consiste%0D%0Aen+desarrollar+un+m%C3%A9todo+constructivo+que+genera+de+forma+aleatoria+una+serie+de+soluciones+iniciales+sobre+las+que+posteriormente+se+aplicar%C3%A1+una+b%C3%BAsqueda+local+cuyo+objetivo+es+mejorar+las+soluciones+iniciales.+Por+%C3%BAltimo+se+aplica+una+versi%C3%B3n+de+la+metaheur%C3%ADstica+Variable%0D%0ANeighborhood+Search+con+la+finalidad+de+evitar+los+%C3%B3ptimos+locales+que+se+producen+con+la+b%C3%BAsqueda+y+tratar+de+alcanzar+un+mejor+resultado.+Los+algoritmos+propuestos+han%0D%0Asido+validados+mediante+la+realizaci%C3%B3n+de+pruebas+que+comparan+los+tres+m%C3%A9todos+desarrollados.+El+tiempo+de+ejecuci%C3%B3n+de+las+pruebas+aumenta+exponencialmente+cuanto+mayor+es+la+dimensi%C3%B3n+de+la+instancia+tratada%2C+siendo+el+tama%C3%B1o+m%C3%A1ximo+que+se+ha+considerado+en+este+proyecto+de+8x8.+Los+resultados+obtenidos+con+el+constructivo+aleatorio+muestran+valores+iniciales+prometedores.+Sin+embargo%2C+esto+parece+indicar+que+los+valores+pueden%0D%0Aestar+pr%C3%B3ximos+a+los+%C3%B3ptimos+locales%2C+siendo+dif%C3%ADcil+la+propuesta+de+algoritmos+de+mejora.+%0D%0AAbtract%3A%0D%0ANowadays%2C+cibersecurity+is+an+important+part+of+the+daily+life+of+many+citizens.+Protecting+data+and+defending+against+attacks+have+already+become+fundamental%2C+and+within+this+area%2C+encrypting+has+become+an+essential+part+in+such+tasks.+This+is+the+reason+why+developing+new+encryption+methods+is+increasingly+important.+On+the+other+hand%2C+Artificial+Ingelligence+has+experienced+a+boom+during+the+last+decade.+Its+techniques+are+gradually+more+used+in+different+contexts%2C+among+which+is+cybersecurity.%0D%0AThis+project+approach+the+aplication+of+Artificial+Intelligence+to+improve+different+aspects+related+to+cryptology%2C+in+the+context+of+cibersecurity.+An+S-Box+is+an+important+component+of+block+ciphers%2C+which+aim+is+transform+a+n+bits+input+into+a+m+bits+output.+For+the+last+decade%2C+some+researchers+have+tried+to+find+new+methods+to+create+S-Boxes.+The+application+of+heuristic+techniques%2C+which+are+part+of+Artificial+Intelligence+context%2C+to+produce+S-Boxes+with+strong+cryptological+properties+has+obtained+more+relevance+compared+to+conventional+methods.+The+approach+proposed+in+this+project+is+to+use+the+scientific+method+in+order+to+generate+an+heuristic+algorithm+to+optimize+some+of+those+S-Boxes+cryptological+properties+(specifically+non+linearity).+To+be+more+accurate%2C+this+project+proposes+developing+a+constructive+method+which+create+a+number+of+solutions+randomly+and+use+a+local+search+in+order+to+improve+the+initial+solutions.+Finally%2C+the+Variable+Neighborhood+Search+metaheuristic+is+applied+trying+to+avoid+local+optima+produced+by+the+local+search+and+improve+the+overall+results.+The+methods+proposed+have+been+validated+with+tests+comparing+the+three+methods.+The+ejecution+time+of+the+tests+increases+exponentially+the+larger+the+size+of+the+instance%2C+being+8x8+the+maximum+size+considered+in+this+project.+The+results+obtained+with+the+random+consctructive+method+shows+promising+initial+values.++However%2C+this+seems+to+indicate+that+those+values+could+be+near+local+optima%2C+making+the+proposal+of+improvement+algorithms+harder.&rft.publisher=E.T.S.I+de+Sistemas+Inform%C3%83%C2%A1ticos+(UPM)&rft.rights=https%3A%2F%2Fcreativecommons.org%2Flicenses%2Fby-nc-nd%2F3.0%2Fes%2F&rft.date=2020-07&rft.type=info%3Aeu-repo%2Fsemantics%2FbachelorThesis&rft.type=Final+Project&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=spa&rft.format=application%2Fzip&rft.language=spa&rft.rights=info%3Aeu-repo%2Fsemantics%2FrestrictedAccess&rft.identifier=https%3A%2F%2Foa.upm.es%2F64788%2F