def mirror_cipher(*message):
    import string
    try:
        txt, key = message
    except ValueError:
        txt = message[0]
        key = string.ascii_lowercase
    txt = txt.lower()
    trantab = txt.maketrans(key, key[::-1])
    return txt.translate(trantab)

6c1cd7fbd37b7563034ee4d2ee9a89ab2439856b
<mask token>

def mirror_cipher(*message):
    import string
    try:
        txt, key = message
    except ValueError:
        txt = message[0]
        key = string.ascii_lowercase
    txt = txt.lower()
    trantab = txt.maketrans(key, key[::-1])
    return txt.translate(trantab)
