You can encrypt a file but you'll only be able to access it from the account you encrypted it from.
1.Right-click on the file/folder you want to encrypt and go to Properties
2.On the General tab, click the Advanced button
3.Under Compress and encrypt attributes section, click on Encrypt content to secure data
4.Click OK and close Properties window
5.Apply changes to the folder, subfolders and files when prompted. Instructions taken from: http://windowsreport.com/encrypt-files-folders-windows-10/