调用两次Encry_pack(),数据就会复原。

/***********************************************************
** @brief  Information encryption.
** @param  key    Random number
** @param  data		Encrypted data
** @param  len		Data length
** @retval None
************************************************************/
const byte odd_keymap[16]  = {0x18, 0x49, 0x8E, 0xF1, 0x6D, 0x3C, 0x2A, 0x5B,0x9D, 0x05, 0xE7, 0x86, 0x32, 0xD6, 0xF2, 0xAC};
const byte even_keymap[16] = {0x97, 0x5A, 0x7F, 0xE0, 0x3B, 0x24, 0x19, 0xF6,0x8A, 0x41, 0x63, 0xB5, 0x72, 0xA8, 0xC4, 0x0D};void Encry_pack(byte key, byte* data)
{byte key_even = even_keymap[(key >> 4) & 0x0F];byte key_odd = odd_keymap[key & 0x0F];for (byte i = 10; i < 22; i++) {data[i] ^= ((i % 2) == 0 ? key_even : key_odd);}
}