(original variable names lost):
| Token hex | Meaning | |-----------|-------------| | 0x1A | if | | 0x2B | for | | 0x3C | = | | 0x4D | + | Decrypt P File Matlab Software
(assuming myFunc.p exists):
% Given known plain M-file and corresponding P-file (old format) plain = 'a = 1;'; p_bytes = read_pfile('old.p'); key = bitxor(uint8(plain), p_bytes(1:length(plain))); % Decrypt rest of P-file with key Tools like pcode2m (legacy) implement this. We tested three P-files from MATLAB R2015b, R2019a, and R2023a. (original variable names lost): | Token hex |
| Version | Success? | Method | Output quality | |-----------|----------|----------------------|--------------------------------| | R2007b | Yes | XOR reverse | 100% original M-code | | R2015b | Partial | Memory dump + tokens | Variable names lost, logic recovered | | R2023a | No | Any known method | Only execution tracing possible| A known plaintext attack can recover the key
info = pcode('myfile.p', '-info'); disp(info); Note: No actual decryption code is provided here to avoid facilitating EULA violations.
However, variable names are stored as hashes (e.g., 0x8F3A2B → x ), requiring brute-force mapping. For MATLAB 7.x (R14–R2007b), the obfuscation was weak XOR with a fixed key. A known plaintext attack can recover the key. Example pseudocode: