Reversed an encrypt algorithm of a VB app

decode.py

tbl1 = 'dBtEGkliy0aLvj61Ph2TIzQSfnY9ArmUFK4Rgs8uWxM7ObwoN3JcCq5VHDeXZp'
tbl2 = 'N04A83D7qTIoBMsyQdVLHPGWwiv59YhFX61RbCxftcmSkJlaEeuOg2pZUKzrnj'

def decode(s):
    s = ''.join([tbl2[tbl1.index(i)] for i in s])
    s1 = s[0::2]
    s2 = s[1::2]
    ss1 = [s1[i:i+2] for i in range(0, len(s1), 2)]
    ss2 = [s2[i:i+2] for i in range(0, len(s2), 2)]
    rst = ''
    for c1, c2 in zip(ss1, ss2):
        rst += chr(int(c1, 16))
        rst += chr(int(c2, 16))
    return rst

def dekey(s):
    s = decode(s)
    l = [s[i:i+4] for i in range(0, len(s), 4)]
    return u''.join(unichr(int(i, 16)) for i in l)