Oracle: V$ENCRYPTED_TABLESPACES

select
   ts#,
   encryptionalg,
   encryptedts,
   encryptedkey,
   masterkeyid,
-- --------------------------------------------------------------------------------------------------------
-- masterkeyid is in Base64 format. 
-- The following transformation returns the key in a format which can be used to
-- compare it to the wallet's ORACLE.SECURITY.DB.ENCRYPTION.MASTERKEY
--     (MOS Note 1228046.1)
   utl_raw.cast_to_varchar2(utl_encode.base64_encode('01'||substr(masterkeyid, 1, 4                  ))) ||
   utl_raw.cast_to_varchar2(utl_encode.base64_encode(      substr(masterkeyid, 5, length(masterkeyid))))     masterkey_, 
-- ------------------------------------------------------------------------------------------------------- 
   blocks_encrypted
   blocks_decrypted,
   key_version,
   status,
   ciphermode,
   con_id
from
   v$encrypted_tablespaces;