is there any program that are made for MAC computers to lock the files
and folders for security?

Yes, there's...
 
LOCK SECRET
- encrypts and decrypts files in batches, and manage encrypted archives. 
http://www.kwerkx.com/rd/products/LockSecret.html
 
 
PDFKey PRO
- unlocks and decrypts password-protected PDF documents. 
http://pdfkey.com/
 
 
iCRYPT
- crypts data using an AES algorithm with 256bits encryption.
http://software.couthouis.com/icrypt/
 
 
SECRET FOLDER
- lets you conceal a folder and its contents. 
http://www.apimac.com/secret_folder/index.php
 
 
eyeHIDE
- enables you to create a hidden folder and access it by entering a password.
http://www.jaanpatterson.com/eyeHide.html
 
 
safeTHIS
- allows you to store sensitive data in encrypted disk images.
http://www.jaanpatterson.com/safeThis.html
 
 
KREMLIN ENCRYPT
- builds a digital wall around your data, protecting your information.
http://www.kremlinencrypt.com/
 
 
 
iCrypt was the most downloaded program on Sofotex:
 
http://mac.sofotex.com/Security/File_Encryption/
 
 
I hope this helps.
 
jackburton-ga