The SQL Server provides several SQL statements to list existing cryptographic keys. The first set of statements shows the SQL Server keys, both keys stored internally and keys with references to EKM providers. This key listing is separated into symmetric and asymmetric listings.
Use the next SQL statement to show the current symmetric keys:
SELECT * from master.sys.symmetric_keys
GO
This will show a listing of current asymmetric keys:
SELECT * from master.sys.asymmetric_keys
GO
Remember that only these keys can be used in SQL statements.
Additionally, all keys stored in the SecurityServer EKM provider can be listed with an extra SQL statement. These keys can be used in a CREATE … KEY statement as PROVIDER_KEY_NAME to create an SQL Server key binding.
SELECT * FROM sys.dm_cryptographic_provider_keys(65536)
GO
Note that the number of shown keys can differ between the previously mentioned SQL statements since not all keys stored in the SecurityServer EKM provider necessarily have an equivalent key in the SQL Server space, and vice versa.