September 2004
Intermediate to advanced
408 pages
7h 25m
English
Content preview from The .NET Developer's Guide to Windows SecurityBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Chapter 13. What Is a SID?
Security Identifiers, or SIDs for short, are used to uniquely identify user and group accounts in Windows. They can be found in tokens (Item 16), in ACLs (Item 43), and in security account databases (Item 12). Most Windows programmers are already familiar with another unique ID, the GUID (or UUID), which is a 128-bit randomly generated identifier used extensively in COM programming. A GUID generated on any machine at any time will be unique from any other GUID because of the large random space from which GUIDs are generated.
The SID is conceptually similar to the GUID in that it also provides uniqueness in space and time. Uniqueness in space is achieved by a 96-bit machine identifier generated at the time the Windows ...