---
title: "Cryptographic Functions (Transact-SQL) | Microsoft Docs"
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  - "functions [SQL Server], cryptographic"
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# Cryptographic functions (Transact-SQL)
[!INCLUDE[tsql-appliesto-ss2008-asdb-xxxx-xxx-md](../../includes/tsql-appliesto-ss2008-asdb-xxxx-xxx-md.md)]

These functions support digital signing, digital signature validation, encryption, and decryption.
  
## Symmetric encryption and decryption
  
|||  
|-|-|  
|[ENCRYPTBYKEY](../../t-sql/functions/encryptbykey-transact-sql.md)|[DECRYPTBYKEY](../../t-sql/functions/decryptbykey-transact-sql.md)|  
|[ENCRYPTBYPASSPHRASE](../../t-sql/functions/encryptbypassphrase-transact-sql.md)|[DECRYPTBYPASSPHRASE](../../t-sql/functions/decryptbypassphrase-transact-sql.md)|  
|[KEY_ID](../../t-sql/functions/key-id-transact-sql.md)|[KEY_GUID](../../t-sql/functions/key-guid-transact-sql.md)|  
|[DECRYPTBYKEYAUTOASYMKEY](../../t-sql/functions/decryptbykeyautoasymkey-transact-sql.md)|[KEY_NAME](../../t-sql/functions/key-name-transact-sql.md)|  
|[SYMKEYPROPERTY](../../t-sql/functions/symkeyproperty-transact-sql.md)||  
  
## Asymmetric encryption and decryption
  
|||  
|-|-|  
|[ENCRYPTBYASYMKEY](../../t-sql/functions/encryptbyasymkey-transact-sql.md)|[DECRYPTBYASYMKEY](../../t-sql/functions/decryptbyasymkey-transact-sql.md)|  
|[ENCRYPTBYCert](../../t-sql/functions/encryptbycert-transact-sql.md)|[DECRYPTBYCERT](../../t-sql/functions/decryptbycert-transact-sql.md)|  
|[ASYMKEYPROPERTY](../../t-sql/functions/asymkeyproperty-transact-sql.md)|[ASYMKEY_ID](../../t-sql/functions/asymkey-id-transact-sql.md)|  
  
## Signing and signature verification
  
|||  
|-|-|  
|[SIGNBYASYMKEY](../../t-sql/functions/signbyasymkey-transact-sql.md)|[VERIFYSIGNEDBYASMKEY](../../t-sql/functions/verifysignedbyasymkey-transact-sql.md)|  
|[SIGNBYCERT](../../t-sql/functions/signbycert-transact-sql.md)|[VERIGYSIGNEDBYCERT](../../t-sql/functions/verifysignedbycert-transact-sql.md)|  
|[IS_OBJECTSIGNED](../../t-sql/functions/is-objectsigned-transact-sql.md)||  
  
## Symmetric decryption, with automatic key handling
  
|||  
|-|-|  
|[DecryptByKeyAutoCert](../../t-sql/functions/decryptbykeyautocert-transact-sql.md)||  
  
## Encryption hashing
  
|||  
|-|-|  
|[HASHBYTES](../../t-sql/functions/hashbytes-transact-sql.md)||  
  
## Certificate copying
  
|||  
|-|-|  
|[CERTENCODED (Transact-SQL)](../../t-sql/functions/certencoded-transact-sql.md)||  
|[CERTPRIVATEKEY (Transact-SQL)](../../t-sql/functions/certprivatekey-transact-sql.md)||  
  
## See also
[Functions](../../t-sql/functions/functions.md)  
[Encryption Hierarchy](../../relational-databases/security/encryption/encryption-hierarchy.md)  
[Permissions Hierarchy (Database Engine)](../../relational-databases/security/permissions-hierarchy-database-engine.md)  
[CREATE CERTIFICATE (Transact-SQL)](../../t-sql/statements/create-certificate-transact-sql.md)  
[CREATE SYMMETRIC KEY (Transact-SQL)](../../t-sql/statements/create-symmetric-key-transact-sql.md)  
[CREATE ASYMMETRIC KEY (Transact-SQL)](../../t-sql/statements/create-asymmetric-key-transact-sql.md)  
[Security Catalog Views (Transact-SQL)](../../relational-databases/system-catalog-views/security-catalog-views-transact-sql.md)