Block access to folder or file in Mac OS X Is there any way to block access to some particular file or folder in MacOS X, so that it can be protected by password?
Not directly - you have to use an app that accesses the file (e.g. a secure note in 1password or a program like gpg or your own app that encrypts/decrypts a file ) or put the file on an encrypted file system (create using Disk Utility or TrueCrypt etc.) See this question for some ways of encrypting.