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Appendix A – Views and Functions ReferenceThis function will return the decrypted value as a varbinary value, whichwill require the use of the CONVERT function to present the decrypted value asreadable text.NOTE:To use symmetric keys in the encryption and decryption process they mustfirst be opened. Once the key is opened, using the OPEN SYMMETRIC KEYcommand, it remains open until it is explicitly closed, using the CLOSESYMMETRIC KEY command, or the session is terminated.USE HomeLending;GOOPEN SYMMETRIC KEY MySymKeyDECRYPT BY PASSWORD = N'MyStr0ngP@ssword2009';GOSELECTConvert(nvarchar(max),DecryptByKey(Identification_Value))FROMdbo.Borrower_IdentificationWHEREBorrower_ID = 1;GOCLOSE SYMMETRIC KEY MySymKey;GOListing A-16: Syntax of DecryptByKey.DecryptByPassphraseThis function is used to decrypt data that has been encrypted with a key that isgenerated from a passphrase. The user performing decryption will require theknowledge of the passphrase that was used during the encryption process.This function will return the decrypted value as a varbinary value, whichwill require the use of the CONVERT function to present the decrypted value asreadable text.USE HomeLending;GO215