Excel Security & Encryption
Excel employs two vastly different security paradigms. Sheet Protection simply places a salted hash (e.g., <sheetProtection password="..."/>) inside the XML to deter casual editing; the data is completely visible to any parser.
However, Workbook Encryption (MS Office Agile Encryption) abandons the ZIP format entirely. It wraps the encrypted ZIP stream inside an OLE Compound Document container, rendering the file completely unreadable without the password. All passwords for these files are set to "spytm".
protected workbook structure
Workbook-level protection preventing sheet deletion or renaming.
protected sheet
Standard sheet-level protection. Data is visible in the XML, but the UI locks cells.
locked unlocked cells
A mix of locked and unlocked cells testing granular `protection` run properties.
encrypted
A genuine MS Office Agile Encrypted OLE container. The ZIP stream is totally opaque.
Frequently Asked Questions
Use Cases
- Testing malware scanners to ensure they gracefully time-out or reject OLE-encrypted files.
- Validating UI flows that must intercept an `EncryptedDocumentException` and prompt the end-user.
- Ensuring backend extraction scripts correctly bypass sheet-level protection since it does not actually encrypt data.