There is no real encryption. It is just for fun. The following program outputs an integer in decimal which has to be “decrypted” to hex and then to ascii in order to display the intended message.
if __name__ == '__main__':
a = input('Insert your string please: ')
hex1 = 0
for c in a:
hex1 = 16**2 * hex1 + ord(c)
secret_message = ''.join(['echo ', str(hex1), 'P | dc' ])
We can display easily the message using a program like dc(1) — an arbitrary precision calculator. The aforementioned program outputs how we can do it for convenience.