In SQL Server, what is the purpose of the WITH ENCRYPTION option when creating stored procedures, and how does it affect the visibility of the procedure definition?

Introduction / Context:
SQL Server allows developers to encrypt the definitions of programmable objects such as stored procedures, views, and functions using the WITH ENCRYPTION option. Interviewers often ask about this feature to check whether candidates understand how code protection works in the database layer. Knowing what WITH ENCRYPTION does and does not do is important for security, maintenance, and troubleshooting decisions.

Given Data / Assumptions:
We are working with stored procedures in Microsoft SQL Server.The WITH ENCRYPTION option is specified when creating or altering the procedure.The goal is to understand how this option affects the visibility of the source definition.We assume normal use of system catalog views and scripting tools to inspect procedures.

Concept / Approach:
When a stored procedure is created using the WITH ENCRYPTION clause, SQL Server stores an obfuscated representation of the procedure definition in the system catalog. As a result, queries against system views such as sys.sql_modules do not reveal the original source text. Tools that script out objects using these views will also fail to show the definition. This can help protect proprietary business logic from casual inspection, although determined attackers may still use advanced methods to attempt decryption. It is important to note that WITH ENCRYPTION does not encrypt table data or network traffic; it only hides the object definition.

Step-by-Step Solution:
Step 1: Recall that the clause WITH ENCRYPTION is part of the CREATE PROCEDURE or ALTER PROCEDURE syntax.Step 2: Remember that its main effect is to hide the procedure source from standard metadata queries and scripting operations.Step 3: Understand that it does not replace other security measures such as permissions, encryption of column data, or TLS configuration.Step 4: Examine the answer choices and select the one that clearly states the code hiding effect.Step 5: Option A matches this precisely, while the other options describe behaviors unrelated to this feature.

Verification / Alternative check:
You can verify the behavior by creating a simple stored procedure with and without WITH ENCRYPTION and then querying sys.sql_modules. For the encrypted version, the definition column will not display the original text, and many tools will show that the object is encrypted. This experiment confirms that the option targets the procedure definition itself, not the data or network, and corresponds directly to the statement in option A.

Why Other Options Are Wrong:
Option B wrongly claims that WITH ENCRYPTION automatically encrypts all table data, which is not true; data encryption uses other features such as Transparent Data Encryption or column level encryption. Option C suggests that network traffic is encrypted, but that is controlled by protocols like TLS, not by a stored procedure option. Option D says the procedure becomes a trigger, which is not how SQL Server works. Option E claims that the procedure runs once and is deleted, which is not an effect of WITH ENCRYPTION.

Common Pitfalls:
Developers sometimes rely on WITH ENCRYPTION as a complete security solution, forgetting that permissions, auditing, and data encryption are still necessary. Another pitfall is that encrypting definitions can make debugging and maintenance more difficult, especially if the source code is not well managed outside the database. Some tools may also be unable to deploy changes if they cannot read the existing definition. Careful planning is needed before applying WITH ENCRYPTION in production environments.

Final Answer:
The correct answer is: It encrypts the stored procedure definition so that its source text is not visible in system views or through standard scripting tools.