Encrypt and Decrypt in SQL Server: Part 3

Introduction

This is Part 3 of the article series. If you have not read Part 1 and Part 2 of the series previously, then please go through the following articles:

1. Encrypt & Decrypt in SQL Server Part-1
2. Encrypt & Decrypt in SQL Server Part-2

In this article, we will generate a certificate and use this certificate to encrypt and decrypt the string.

Create Certificate

CREATE CERTIFICATE TESTCERT   ENCRYPTION BY PASSWORD  = '@k$h@yPatel'    WITH SUBJECT  = 'TEST CERTIFICATE', 
   START_DATE = '01/10/2013', 
    EXPIRY_DATE = '01/10/2014'   

If start_date is not provided, then the current date will be startdate, and if expiry_date is not provided, then startdate will be considered after one year.

Backup Certificate

BACKUP CERTIFICATE TESTCERT   TO FILE  =   'd:\TestCert.CER'    WITH PRIVATE KEY   (
           FILE = 'd:\TestCert.PVK', 
           ENCRYPTION BY PASSWORD = '@k$h@yPatel', 
           DECRYPTION BY PASSWORD = '@k$h@yPatel'   
)    GO  

Restore Certificate

DROP CERTIFICATE TESTCERT  
CREATE CERTIFICATE TESTCERT  
FROM FILE='D:\TestCert.CER'  

Encrypt & Decrypt 

DECLARE @Text VARCHAR(50)  
DECLARE @EncryptedText VARBINARY(128)  
DECLARE @DecryptedText VARCHAR(MAX)  
SET @Text = 'I am Akshay Patel'  
SET @EncryptedText=ENCRYPTBYCERT(CERT_ID('TESTCERT'),@Text)  
SET @DecryptedText=DECRYPTBYCERT(CERT_ID('TESTCERT'),@EncryptedText,N'@k$h@yPatel')  
SELECT @Text AS 'TextToEncrypt',@EncryptedText AS 'EncryptedText',@DecryptedText as 'DecryptedText'  

Conclusion

In the next article, we will generate an asymmetric key and encrypt and decrypt the string using public and private keys.

Next- Encrypt and Decrypt in SQL Server: Part 4