The encryption key and rights digest method must be defined as part of a vendor specific
toolblock. These are a set of mandatory pragmas which define the
vendor public encryption key, key related attributes, and method for calculating the
digest for rights in the toolblock of each vendor. The following
example shows these pragmas and their valid values for AMD.
`protect key_keyowner = "Xilinx"
`protect key_method = "rsa"
`protect key_keyname = "xilinxt_2019_11"
`protect rights_digest_method = "sha256"
`protect key_public_key
...