Quantum technology startup Quantum Optics Jena (QOJ) has closed an €8.5 million (~$9.4 million) Series A funding round. The funds will be used to fuel QOJ’s expansion and accelerate the commercialization of its quantum key distribution technology. QOJ is utilizing entangled photon pairs for tap-proof communication. The photons generate a 'key' which is used to encrypt and decrypt data — a method known as entanglement-based key distribution (EKD). With this approach, multiple users can securely communicate at the same time by using the generated quantum keys. QOJ also develops hardware, software, and services for data exchange for customers with high security requirements, such as government networks and banks. The company is now working to build a communication system with partners in the rural area surrounding Jena to securely send information and patient data to the Jena University Hospital. The company is also involved in the construction of a European Quantum Communication Infrastructure, which is expected to be operational across all of Europe by 2027. The company is active in in Singapore, Spain, Austria, and Slovakia, and has a sales office in North Carolina. The funding round was led by venture capital firm Join Capital and joined by early investors ELAS Technologies GmbH, Fraunhofer Technologies-Transfer Fonds, and beteiligungsmanagement Thüringen as well as angel investor Malte Pollmann.