01679nas a2200205   4500000000100000000000100001008004100002653002100043653001800064653001700082653000800099653002100107653002000128100001900148700002300167245011700190300001100307490000700318520114800325       2017                            d10acapture the flag10acollaboration10acryptography10aCTF10acyber resilience10aproblem-solving1 aGeorge Sharkov1 aChristina Todorova00aCapture the Flag for Cyber-Resilience Exercising through Cryptographic Puzzles and Collaborative Problem-Solving  a95-1020 v373 a<p>The importance of cybersecurity in the digital society and our daily lives is becoming increasingly apparent. With the rise of digital reliance, securing information, whether this information is at rest, in transit, or in use, is vital to ensuring the interoperability of systems, including critical infrastructure, on which society’s physical well-being depends. Cryptography is well-known for its role in cybersecurity as a crucial tool for protecting information exchanged via digital devices.<br>Cryptography is the science of concealing information so that only the intended parties can read it. As a result, we may generalise that cryptography enables people to communicate via the Internet while securely sending critical and secret information. However, cryptography is a relatively complex combination of mathematics and computer science, where typical learning methodologies may fall short when it comes to achieving hands-on expertise. This paper provides an overview of the possibilities of Capture the Flag (CTF) exercises to test cybersecurity capabilities using collaborative methodologies and cryptographic challenges.</p>