ASYM_KEY_1024

### ASYM_KEY_1024 in SQL Server Asymmetric Key Encryption Configuration and Usage

In SQL Server, an asymmetric key such as `ASYM_KEY_1024` is used for various cryptographic operations including encrypting data, signing objects, and protecting other keys. The size of the key (`1024`) indicates that this particular asymmetric key uses a 1024-bit length which was common but now considered less secure compared to longer bit lengths like 2048 or higher.

To create an asymmetric key with a specific algorithm and bit-length within SQL Server:

CREATE ASYMMETRIC KEY ASYM_KEY_1024 WITH ALGORITHM = RSA_1024;

This command creates an asymmetric key named `ASYM_KEY_1024`, using the RSA algorithm at 1024 bits[^1].

For utilizing this newly created asymmetric key to perform encryption on some plaintext value stored inside a variable called @PlainTextValue:

DECLARE @EncryptedData varbinary(256);
SET @EncryptedData = ENCRYPTBYASYMKEY(AsymKey_ID('ASYM_KEY_1024'), 'Your Plain Text Here');
SELECT @EncryptedData AS EncryptedData;

Decryption can be performed similarly when having access rights to the private part of the asymmetric key pair:

DECLARE @DecryptedData nvarchar(max);
SET @DecryptedData = CAST(DECRYPTBYASYMKEY(AsymKey_ID('ASYM_KEY_1024'),
    @EncryptedData) AS NVARCHAR(MAX));
SELECT @DecryptedData AS DecryptedText;

It's important to note that while creating non-symmetric keys from assemblies might require enabling certain settings due to security policies, direct creation through T-SQL does not necessitate altering server-level configurations unless additional permissions are required. However, always ensure best practices regarding strong naming and protection mechanisms during deployment phases especially involving external components or modules.