Workshop organized by ICFO – The Institute of Photonic Sciences as part of the International Year of Quantum Science, dedicated to exploring how quantum physics can ensure the security of our digital communications. In a world where most sensitive information —financial, medical, or personal— travels through the internet, quantum cryptography provides a system capable of detecting any attempt at eavesdropping and protecting data through 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 technology can make the communications of the future more secure.