Including Rails classes in a rake task?

I'm pretty new to Rails, so I apologize if my question doesn't make the most sense. I have a class called `PaymentGatewayCipher` that looks like: ``` require 'openssl' # Encapsulates payment gateway encryption / decryption utility functions class PaymentGatewayCipher class << self def encrypt(file, options = {}) cipher = create_cipher cipher.encrypt(cipher_key) data = cipher.update(File.read(file)) data << cipher.final if to_file = options[:to] # Write it out to a different file File.open(to_file, 'wb') do |f| f << data end end data end # Decrypts the given file def decrypt(file) cipher = create_cipher cipher.decrypt(cipher_key) encrypted_data = File.open(file, 'rb') {|io| io.read} data = cipher.update(encrypted_data) data << cipher.final end # Generates the cipher to be used for encryption/decryption def create_cipher OpenSSL::Cipher::Cipher.new('aes-256-cbc') end # Loads the cipher key used for the symmetric algorithm def cipher_key File.open(File.join(Rails.root, 'config/mystuff/live/cipher.key'), 'rb') {|io| io.read} end end end ``` I want to write a `rake task` to run it to decrypt a file. I've tried putting a file in `tasks/Rakefile` that looks like: ``` directory "tasks" task :decrypt_test do puts "Decypting" pay_pal_config = PaymentGatewayCipher.decrypt('hpa1') end ``` When I run it, however, it says cannot find `Class::Rails` Help?