You can choose an advanced encryption level to protect your drawing.
A default encryption level, supplied by your operating system, is used unless you choose an advanced level. If you decide to choose an advanced level, you can choose from RC4 encryption providers supplied by your operating system. You also can choose a key length (the higher the length, the higher the protection). An RC4 encryption provider is a standard form of encryption, and the RC4 encryption providers vary in the type of protection they provide.
Before using an advanced encryption level (provider, type, and key length), confirm that any computer that needs to decrypt the drawing has the cryptography service provider you plan to use. For more information on cryptography providers, encryption types, and encryption key lengths, search the Internet for these terms.