4 ms·

… and no, since neither the enciphering nor the deciphering do a 1:1 mapping for all possible input code points.

• amenhotep 1y ago
  That's not a requirement. Pigpen is a substitution cipher.
  • JdeBP 1y ago
    You will find that the pigpen cipher has a 1:1 mapping between its input alphabet and its output alphabet, and that a 1:1 mapping is a necessity for full invertibility.