Engage Black is a hardware security company based in Aptos, California, that designs, fabricates, and assembles its products in the United States. The company develops and sells cryptographic hardware and encryption appliances for securing data at rest and data in motion. Their primary product line centers on the BlackVault Hardware Security Module (HSM), available in multiple variants including the BlackVault HSM, HSM.TAC, HSM.RAS, and HSM.TSA (Time Stamp Authority). These HSMs are used for cryptographic key management, certificate authority (CA) functions, code signing, document signing, and Bring Your Own Key (BYOK) integrations with major cloud platforms including Microsoft Azure, AWS, and Google Cloud. For data-in-motion encryption, Engage Black offers the BlackDoor product family, which includes Ethernet encryptors at various speeds (10/100 and Gigabit), as well as the BlackSER AES for serial encryption and the BlackBond and BlackTube product lines for circuit encryption covering T1, E1, and RS232 configurations. The company also provides the BlackVault CA, a dedicated certificate authority appliance, and supports integrations with third-party CA systems including Microsoft Certificate Authority, Red Hat Certificate System, EJBCA, and ISC's CertAgent. Utility software such as BVTool and BVImport support device management and key import operations. Engage Black's solutions address use cases including PKI infrastructure, code integrity verification, secure communications for enterprise and government environments, and cloud key sovereignty.