7-Zip method IDs (9.24)
-----------------------

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 

   F0 - Ciphers without hashing algo

      01 - AES
         0x - AES-128
         4x - AES-192
         8x - AES-256
         Cx - AES

         x0 - ECB
         x1 - CBC
         x2 - CFB
         x3 - OFB
         x4 - CTR

   F1 - Combine Ciphers
      01 - Zip
         01 - Main Zip crypto algo
      03 - RAR
         02 - 
         03 - Rar29 AES-128 + (modified SHA-1)
      07 - 7z
         01 - AES-256 + SHA-256


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End of document
