https://cryptopals.com/ - desafios de crypto geral https://microcorruption.com/login - joguinho de crypto https://www.offsec.com/courses-and-certifications/ - cursos (caros!) https://www.schneier.com/blog/archives/2008/03/the_security_mi_1.html - um post interessante de um blog interessante https://pentesterlab.com - treino para teste de penetração (pago!) https://littlemaninmyhead.wordpress.com/2017/04/22/top-10-developer-crypto-mistakes/ - blog sobre erros frequentes em segurança