Figure 3
At the top are four external data sources represented by cylinders: “Keystore,” “Legacy Database,” “Authentication Database,” and “Cacher.” Below these are four blocks labeled “Ethsigner,” “Legacy Database,” “Device Simulator,” and “Authentication Database.” Below these blocks is a larger rectangle labeled “Blockchain,” which contains another rectangle labeled “Write Policy.” Within “Write Policy” are four blocks titled “Read Policy,” each containing a circle labeled “Besu Node.” The top, right, bottom, and left “Read Policy” blocks all contain a “Besu Node.” Arrows represent flows between elements as follows: A bidirectional arrow connects “Keystore” and “Ethsigner.” Another bidirectional arrow connects “Authentication database” and “Keycloak.” An arrow labeled “!” from “Legacy Database” leads to “Device Simulator.” An arrow labeled “2” flows from “Device Simulator” to “Keycloak.” An arrow labeled “3” flows from “Keycloak” to “Device Simulator.” An arrow labeled “4” flows from “Device Simulator” to “Ethsigner.” An arrow labeled “5” flows from “Ethsigner” to “Device Simulator.” An arrow labeled “6” flows from “Device Simulator” to top “Besu Node.” An arrow labeled “7” flows from “Cacher” to “Keycloak.” An arrow labeled “8” flows from “Keycloak” to “Cacher.” An arrow labeled “9” flows from top “Besu Node” to “Cacher.” An arrow labeled “10” flows from “Cacher” to “Cache Database.”Architecture of our solution