validates :timestamp, :presence => true
validates :nonce, :presence => true, :uniqueness => { :scope => :timestamp }
# Remembers a nonce and it's associated timestamp. It returns false if it has already been used
def self.remember(nonce, timestamp)
validates :timestamp, :presence => true
validates :nonce, :presence => true, :uniqueness => { :scope => :timestamp }
# Remembers a nonce and it's associated timestamp. It returns false if it has already been used
def self.remember(nonce, timestamp)