What is Microsoft Office password protection?

Office 2007-2013 used 128-bit key and Office 2016 using 256-bit key AES password protection which also remains secure. Office 97-2003 password protection used 40-bit key RC4 contains multiple vulnerabilities, making it insecure. Microsoft Office password protection application mainly concentrates on the main groups of passwords that can be easily set to the documents depending on encrypt password-protected document or not. http://setup-product-key.com/what-is-microsoft-office-password-protection/