While blockchain services hold great promise to improve many different industries, there are significant cybersecurity concerns which must be addressed. In this paper, we present experimental test bed results for a novel method of user identity management for cloud-based blockchain applications. Using a BlackRidge Technology endpoint on a Windows host, we insert cryptographic identity tokens on the
first packet to request a new session. A corresponding gateway appliance in the cloud enforces security policy, blocking
unauthorized access at or below the transport layer. Results of penetration testing a sample Hyperledger 1.0 application are discussed. We also demonstrate network segmentation and
traffic separation, which allows multiple organizations to share blockchain infrastructure and facilitates compliance auditing.