What term denotes the unique identifier assigned to a Windows account by the operating system?

What term denotes the unique identifier assigned to a Windows account by the operating system?

• A. User Principal Name (UPN)
• B. ObjectGUID
• C. Access token
• D. Security identifier (SID)

Answer: (D)

Windows uses a Security Identifier, or SID, as the unique identifier for every account. When an account is created, the OS assigns a SID and it stays with that account across name changes; in a domain, the overall SID is built from the domain’s SID plus a relative identifier (RID) for the specific account, ensuring true uniqueness. The SID is the value the system uses in access control lists to attach permissions and in the security token presented during authentication and authorization. This is different from a User Principal Name, which is just a user-friendly login name; ObjectGUID is an AD-specific directory object identifier; and an access token is a runtime structure that carries the account’s SID among other data, not the persistent identifier itself.

Windows uses a Security Identifier, or SID, as the unique identifier for every account. When an account is created, the OS assigns a SID and it stays with that account across name changes; in a domain, the overall SID is built from the domain’s SID plus a relative identifier (RID) for the specific account, ensuring true uniqueness. The SID is the value the system uses in access control lists to attach permissions and in the security token presented during authentication and authorization. This is different from a User Principal Name, which is just a user-friendly login name; ObjectGUID is an AD-specific directory object identifier; and an access token is a runtime structure that carries the account’s SID among other data, not the persistent identifier itself.