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markup fix + note about MAX_DATA_SIZE

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elandorr 2023-05-14 07:14:48 +00:00 committed by GitHub
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commit e086d2a8f6
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55
src/borg/archiver/help_cmd.py
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@ -385,29 +385,44 @@ class HelpMixIn:
obfuscate,SPEC,C[,L]
Use compressed-size obfuscation to make fingerprinting attacks based on
the observable stored chunk size more difficult.
Note:
- you must combine this with encryption or it won't make any sense.
- your repo size will be bigger, of course.
the observable stored chunk size more difficult. Note:
The SPEC value will determine how the size obfuscation will work:
- You must combine this with encryption, or it won't make any sense.
- Your repo size will be bigger, of course.
- A chunk is limited by the constant ``MAX_DATA_SIZE`` (cur. ~20MiB).
The SPEC value determines how the size obfuscation works:
*Relative random reciprocal size variation* (multiplicative)
Relative random reciprocal size variation:
Size will increase by a factor, relative to the compressed data size.
Smaller factors are often used, larger factors rarely.
1: factor 0.01 .. 100.0
2: factor 0.1 .. 1000.0
3: factor 1.0 .. 10000.0
4: factor 10.0 .. 100000.0
5: factor 100.0 .. 1000000.0
6: factor 1000.0 .. 10000000.0
Smaller factors are used often, larger factors rarely.
Add a randomly sized padding up to the given size:
110: 1kiB
...
120: 1MiB
...
123: 8MiB (max.)
Available factors::
1: 0.01 .. 100
2: 0.1 .. 1,000
3: 1 .. 10,000
4: 10 .. 100,000
5: 100 .. 1,000,000
6: 1,000 .. 10,000,000
Example probabilities for SPEC ``1``::
90 % 0.01 .. 0.1
9 % 0.1 .. 1
0.9 % 1 .. 10
0.09% 10 .. 100
*Randomly sized padding up to the given size* (additive)
::
110: 1kiB (2 ^ (SPEC - 100))
...
120: 1MiB
...
123: 8MiB (max.)
Examples::
@ -418,7 +433,7 @@ class HelpMixIn:
borg create --compression zlib,1 REPO::ARCHIVE data
borg create --compression auto,lzma,6 REPO::ARCHIVE data
borg create --compression auto,lzma ...
borg create --compression obfuscate,3,none ...
borg create --compression obfuscate,110,none ...
borg create --compression obfuscate,3,auto,zstd,10 ...
borg create --compression obfuscate,2,zstd,6 ...\n\n"""
)