1 7-Zip method IDs (4.56)
2 -----------------------
4 Each compression or crypto method in 7z has unique binary value (ID).
5 The length of ID in bytes is arbitrary but it can not exceed 63 bits (8 bytes).
7 If you want to add some new ID, you have two ways:
8 1) Write request for allocating IDs to 7-zip developers.
9 2) Generate 8-bytes ID:
11 7F ZZ ZZ ZZ ZZ ZZ MM MM
13 7F - Prefix for random IDs (1 byte)
14 ZZ ZZ ZZ ZZ ZZ - Developer ID (5 bytes). Use real random bytes.
16 MM MM - Method ID (2 bytes)
18 You can notify 7-Zip developers about your Developer ID / Method ID.
20 Note: Use new ID only if old codec can not decode data encoded with new version.
32 04 Delta (subject to change)
43 05 - BC_PPC_B (Big Endian)
51 05 - BC_M68_B (Big Endian)
61 01 - experimental methods.
63 80 - reserved for independent developers
70 00 - Copy (not used). Use {00} instead
75 12 - BZip2 (not used). Use {04 02 02} instead
110 F0 - Misc Ciphers (Real Ciphers without hashing algo)
112 F1 - Misc Ciphers (Combine)
114 01 - Main Zip crypto algo
117 03 - Rar29 AES-128 + (modified SHA-1)
119 01 - AES-256 + SHA-256
121 07 - Hash (subject to change)
133 03 - Rar29 Password Hashing (modified SHA1)
135 01 - SHA-256 Password Hashing