[1] Digi-CA uses a PKCS#11 API standard to perform Cryptographic functions using either HSM devices or using its own Cryptoki application based layer.
Links:[1] https://www.digi-sign.com/downloads/download.php?id=digi-ca-pdf
[1] Digi-CA uses a PKCS#11 API standard to perform Cryptographic functions using either HSM devices or using its own Cryptoki application based layer.