Storing Keys of Multiple Issuers

Hi, I’m (newbie) trying to support a solution which would securely store the private and public key pairs of multiple issuers. Imagine a multi- tenant solution supporting multiple issuers that would allow multiple universities to generate/sign credentials with thier key pairs. Wanted to understand methods others have used generate (which algorithms are supported on Bitcoin) and safely store the keys (AWS KMS?). I understand that the students would use the IOS or Android app to store the private and public key pair and their credentials.