Brute-force attacks are fairly simple to understand, but difficult to protect against. Encryption is math, and as computers become faster at math, they become faster. Explains how to encrypt and decrypt data using a symmetric key algorithm and salt to prevent dictionary attacks in C# or VisualBasic.NET. Simple String Encryption and Decryption. Encrypting and decrypting strings in T- SQL code is complicated in SQL Server 2. You have to use the undocumented PWDEncrypt and PWDCompare functions or use symmetric (i. Fortunately, encrypting and decrypting strings in T- SQL code is much easier in SQL Server 2. SQL Server 2. 00. One of the easiest ways is to use the ENCRYPTBYPASSPHRASE and DECRYPTBYPASSPHRASE functions. Related: Decrypt SQL Server Objects To demonstrate the ease of using ENCRYPTBYPASSPHRASE and DECRYPTBYPASSPHRASE, I created two simple functions: dbo. Encrypt and dbo. Decrypt. Example 9: My personal blog Sometimes I use encryption on my personal blog to keep things hidden from prying eyes. Most of my blog can be viewed by anyone, but every. Caesar Cipher in Java. Transparent Data Encryption is designed to protect data by encrypting the physical files of the database, rather than the data itself. Its main purpose is to prevent. RC4 Encryption - Encrypt/decrypt your data with a key of your choice. The dbo. Encrypt function encrypts the plaintext that you pass to it, whereas the dbo. Decrypt function decrypts the ciphertext you pass in. In this case, the passphrase is 'SQL SERVER 2. As the latter demonstrates, you have the option of storing either of these arguments in variables. Like the ENCRYPTBYPASSPHRASE function, the DECRYPTBYPASSPHRASE function has two mandatory arguments: a passphrase (which will be used to generate the decryption key) and the ciphertext to decrypt. In this case, the passphrase is 'SQL SERVER 2. Next, the code uses the dbo. Decrypt function to decrypt the string in @code, stores the result (i. Eli Leiba is A SQL guru') in the @x variable, then prints it. However, there's a caveat—you're responsible for managing and securing the passphrase. By default, no permissions are required to execute the ENCRYPTBYPASSPHRASE and DECRYPTBYPASSPHRASE functions and you don't have the ability to select the algorithm they use for encryption and decryption. So, depending on how your SQL Server environment is set up, a few people might be able to see the passphrase and even execute the dbo. Encrypt and dbo. Decrypt functions if they had access to their code. For example, the code in Listing 4 creates a table named pass. Phrase. Encoders and inserts the 'SQL SERVER 2. Listing 4: Code That Creates and Loads the pass. Phrase. Encoders Table After you give this table the necessary permissions, you need to create a synonym named pass. Phrase. Encoders for master. Phrase. Encoders in the application database. In the dbo. Encrypt function in Listing 1, you need to replace the line in callout A with the code DECLARE @pass. Phrase varchar(8. SELECT @pass. Phrase = Pass. Only reliable DBAs and trusted individuals should create these functions. It's also a good practice to create them with the ENCRYPTION clause. Consequently, you might not want to use the dbo. Encrypt and dbo. Decrypt functions for encrypting text just before exporting it out of your database to an exposed text file, for example.
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