This password is stored
inside the document.
You can see it using any HEX-viewer.
Document protection
password.
Password hash is stored in
the document.
Hash length is only 32 bits. We can change this password to any other one, or disable it
(replace with a hash of an empty string).
Password to open
When this password is set, the entire Word document (including a part of auxiliary information) is encrypted with the RC4 algorithm (stream cipher). 128-bit long hash formed with the MD5 algorithm is used for password verification. Encryption key is 40-bit long, because state regulations of many countries don’t allow using stronger crypto.
Book and Sheet password.
When an Excel Sheet is being protected with a password, a 16-bit (two byte) long hash is generated. Book protection is somewhat more sophisticated. Hash generation algorithm is the same as with sheet protection, however, a whole document is being encrypted. Password for encryption is “VelvetSweatshop”.