class ActiveRecord::Encryption::Key

references the key for a future retrieval operation.
in clean (public) and can be used, for example, to include information that
Optionally, it can include public_tags. These tags are meant to be stored
A key is a container for a given secret

def self.derive_from(password) 

def self.derive_from(password)
  secret = ActiveRecord::Encryption.key_generator.derive_key_from(password)
  ActiveRecord::Encryption::Key.new(secret)
end

def id 

def id
  Digest::SHA1.hexdigest(secret).first(4)
end

def initialize(secret) 

def initialize(secret)
  @secret = secret
  @public_tags = Properties.new
end