code: def _decryptChar(cipher, R):
      cipher = byteord(cipher)
      plain = ((cipher ^ (R >> 8))) & 0xFF
      R = ((cipher + R) * 52845 + 22719) & 0xFFFF
      return bytechr(plain), R
  
imports: from fontTools.misc.textTools import bytechr, bytesjoin, byteord
label_desc: Use image node_id 1 for calling a global function with example usage: _decryptChar(cipher, R) and returns: bytechr,  R