In some examples, a first computing device of a first entity receives a first digital certificate from a certificate authority computing device and generates a first self-signed certificate associated with the first digital certificate. The first computing device may store the first self-signed certificate associated with the first digital certificate in a repository associated with a repository computing device. Further, the first computing device may receive a notification indicating an update by a computing device of a second entity to contents of the repository. The first computing device receives a copy of the contents of the repository including at least a second digital certificate and a second self-signed certificate associated with the second entity. The first computing device may verify the contents of the repository and generate a genesis block of a blockchain based on a result of the verifying.