Workshop organized by ICFO – Institute of Photonic Sciences within the framework of the International Year of Quantum, dedicated to exploring how quantum physics can guarantee the security of our digital communications. In a world where most of the sensitive information —financial, medical or personal— circulates on the internet, quantum cryptography offers a system capable of detecting any attempt at espionage and protecting data using the properties of photons. Participants will be able to reproduce an optical communication system and create their own cryptographic code to experience, in a practical and playful way, how quantum can make future communications more secure.