def decrypt(value)
      return value if is_empty_val(value)
      c = cipher.decrypt
      c.key = Digest::SHA256.digest(cipher_key)
      c.iv = Base64.decode64 value.slice!(0,25)
      c.update(Base64.decode64(value.to_s)) + c.final
    end
def decrypt(value)
      return value if is_empty_val(value)
      c = cipher.decrypt
      c.key = Digest::SHA256.digest(cipher_key)
      c.iv = Base64.decode64 value.slice!(0,25)
      c.update(Base64.decode64(value.to_s)) + c.final
    end
Decrypts model attribute value