A simple cryptography to encode and decode a payload based on OpenSSL::Cipher

class SimpleCryptography
  SECRET = "secretkey"

  def self.encode payload
    cipher = OpenSSL::Cipher.new('AES-128-CBC').encrypt
    cipher.key = Digest::SHA1.hexdigest(SECRET).unpack('B16').first
    s = cipher.update(payload) + cipher.final
    s.unpack('H*')[0].upcase
  end

  def self.decode enrypted_payload
    cipher = OpenSSL::Cipher.new('AES-128-CBC').decrypt
    cipher.key = Digest::SHA1.hexdigest(SECRET).unpack('B16').first
    s = [payload].pack("H*").unpack("C*").pack("c*")
    cipher.update(s) + cipher.final
  end
end

Example

payload = "1234567890"

# encode
enrypted_payload = SimpleCryptography.encode(payload)

# decode
decrypted_payload = SimpleCryptography.decode(enrypted_payload)

# compare the decoded payload with actual payload
decrypted_payload == payload