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17-Zip method IDs for 7z and xz archives
2---------------------------------------
3
4Version: 23.01
5Date: 2023-06-30
6
7Each compression or crypto method in 7z is associated with unique binary value (ID).
8The length of ID in bytes is arbitrary but it can not exceed 63 bits (8 bytes).
9
10xz and 7z formats use same ID map.
11
12If you want to add some new ID, you have two ways:
13  1) Write request for allocating IDs to 7-Zip developers.
14  2) Generate 8-bytes ID:
15
16    3F ZZ ZZ ZZ ZZ ZZ MM MM
17
18    3F              - Prefix for random IDs (1 byte)
19    ZZ ZZ ZZ ZZ ZZ  - Developer ID (5 bytes). Use real random bytes.
20
21    MM MM           - Method ID (2 bytes)
22
23    You can notify 7-Zip developers about your Developer ID / Method ID.
24
25    Note: Use new ID, if old codec can not decode data encoded with new version.
26
27
28List of defined IDs
29-------------------
30
3100 - Copy
32
3303 - Delta
3404 - BCJ (x86)
3505 - PPC (big-endian)
3606 - IA64
3707 - ARM (little-endian)
3808 - ARMT (little-endian)
3909 - SPARC
400A - ARM64
41
4221 - LZMA2
43
4402.. - Common
45   03 [Swap]
46      - 2 Swap2
47      - 4 Swap4
48
4903.. - 7z
50   01 -
51      01 - LZMA
52
53   03 - [Branch Codecs]
54      01 - [x86 Codecs]
55         03  - BCJ
56         1B  - BCJ2 (4 packed streams)
57      02 -
58         05 - PPC (big-endian)
59      03 -
60         01 - Alpha
61      04 -
62         01 - IA64
63      05 -
64         01 - ARM (little-endian)
65      06 -
66         05 - M68 (big-endian)
67      07 -
68         01 - ARMT (little-endian)
69      08 -
70         05 - SPARC
71
72   04 -
73      01 - PPMD
74
75   7F -
76      01 - experimental method.
77
78
7904.. - Misc codecs
80
81   00 - Reserved
82
83   01 - [Zip]
84      00 - Copy (not used. Use {00} instead)
85      01 - Shrink
86      06 - Implode
87      08 - Deflate
88      09 - Deflate64
89      0A - Imploding
90      0C - BZip2 (not used. Use {040202} instead)
91      0E - LZMA (LZMA-zip)
92
93      5D - ZSTD
94      5F - xz
95      60 - Jpeg
96      61 - WavPack
97      62 - PPMd (PPMd-zip)
98      63 - wzAES
99
100   02 -
101      02 - BZip2
102
103   03 - [Rar]
104      01 - Rar1
105      02 - Rar2
106      03 - Rar3
107      05 - Rar5
108
109   04 - [Arj]
110      01 - Arj(1,2,3)
111      02 - Arj4
112
113   05 - [Z]
114
115   06 - [Lzh]
116
117   07 - Reserved for 7z
118
119   08 - [Cab]
120
121   09 - [NSIS]
122      01 - DeflateNSIS
123      02 - BZip2NSIS
124
125   F7 - External codecs (that are not included to 7-Zip)
126
127      0x xx - reserved
128
129      10 xx - reserved (LZHAM)
130         01 - LZHAM
131
132      11 xx - reserved (Tino Reichardt)
133         01 - ZSTD
134         02 - BROTLI
135         04 - LZ4
136         05 - LZ5
137         06 - LIZARD
138
139      12 xx - reserverd (Denis Anisimov)
140
141         01 - WavPack2
142         FE - eSplitter
143         FF - RawSplitter
144
145
14606.. - Crypto
147
148   F0 - Ciphers without hashing algo
149
150      01 - [AES]
151         0x - AES-128
152         4x - AES-192
153         8x - AES-256
154         Cx - AES
155
156         x0 - ECB
157         x1 - CBC
158         x2 - CFB
159         x3 - OFB
160         x4 - CTR
161
162   F1 - Combine Ciphers
163
164      01 - [Zip]
165         01 - ZipCrypto (Main Zip crypto algo)
166
167      03 - [RAR]
168         02 -
169         03 - Rar29AES (AES-128 + modified SHA-1)
170
171      07 - [7z]
172         01 - 7zAES (AES-256 + SHA-256)
173
174
175---
176End of document
177