7-Zip method IDs (9.18) ----------------------- Each compression or crypto method in 7z has unique binary value (ID). The length of ID in bytes is arbitrary but it can not exceed 63 bits (8 bytes). If you want to add some new ID, you have two ways: 1) Write request for allocating IDs to 7-zip developers. 2) Generate 8-bytes ID: 3F ZZ ZZ ZZ ZZ ZZ MM MM 3F - Prefix for random IDs (1 byte) ZZ ZZ ZZ ZZ ZZ - Developer ID (5 bytes). Use real random bytes. MM MM - Method ID (2 bytes) You can notify 7-Zip developers about your Developer ID / Method ID. Note: Use new ID only if old codec can not decode data encoded with new version. List of defined IDs ------------------- 00 - Copy 03 - Delta 04 - x86 (BCJ) 05 - PPC (Big Endian) 06 - IA64 07 - ARM (little endian) 08 - ARM Thumb (little endian) 09 - SPARC 21 - LZMA2 02.. - Common 03 Swap - 2 Swap2 - 4 Swap4 03.. - 7z 01 - LZMA 01 - Version 03 - Branch 01 - x86 03 - BCJ 1B - BCJ2 02 - PPC 05 - PPC (Big Endian) 03 - Alpha 01 - Alpha 04 - IA64 01 - IA64 05 - ARM 01 - ARM 06 - M68 05 - M68 (Big Endian) 07 - ARM Thumb 01 - ARMT 08 - SPARC 05 - SPARC 04 - PPMD 01 - Version 7F - 01 - experimental methods. 04.. - Misc 00 - Reserved 01 - Zip 00 - Copy (not used). Use {00} instead 01 - Shrink 06 - Implode 08 - Deflate 09 - Deflate64 10 - Imploding 12 - BZip2 (not used). Use {04 02 02} instead 14 - LZMA 60 - Jpeg 61 - WavPack 62 - PPMd 63 - wzAES 02 - BZip 02 - BZip2 03 - Rar 01 - Rar15 02 - Rar20 03 - Rar29 04 - Arj 01 - Arj (1,2,3) 02 - Arj 4 05 - Z 06 - Lzh 07 - Reserved for 7z 08 - Cab 09 - NSIS 01 - DeflateNSIS 02 - BZip2NSIS 06.. - Crypto 00 - 01 - AES 0x - AES-128 4x - AES-192 8x - AES-256 Cx - AES x0 - ECB x1 - CBC x2 - CFB x3 - OFB 07 - Reserved 0F - Reserved F0 - Misc Ciphers (Real Ciphers without hashing algo) F1 - Misc Ciphers (Combine) 01 - Zip 01 - Main Zip crypto algo 03 - RAR 02 - 03 - Rar29 AES-128 + (modified SHA-1) 07 - 7z 01 - AES-256 + SHA-256 07.. - Hash (subject to change) 00 - 01 - CRC 02 - SHA-1 03 - SHA-256 04 - SHA-384 05 - SHA-512 F0 - Misc Hash F1 - Misc 03 - RAR 03 - Rar29 Password Hashing (modified SHA1) 07 - 7z 01 - SHA-256 Password Hashing --- End of document