I have managed to make a VeraCrypt Traveler Disk fit on a 1.44 MB 3.5¨ floppy disk with 34 KB to spare using strong self-extracting compression.
Now I want to minimize the overhead of the encrypted FAT container created on another second floppy disk.
Allocating the full microfloppy capacity of 1.44 MB, the mounted VeraCrypt volume has a capacity reduction of -299 KB. This leaves less than 80 % of usable FAT12 space remaining on the disk.
Is there any way to increase the portion of free space? Where did it go?
I need to use no more than two 3.5¨ floppy disks in total or else there is unnecessary hassle and an additional surcharge mailing fee due to the extra weight of an additional disk when sending sensitive files/data off-line. This is of course not an issue when burning CD/DVDs, however they aren't as volatile and are more difficult to erase/destroy after use.
Last edit: 2024-08-13
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You’ve done an impressive job fitting a VeraCrypt Traveler Disk onto a 1.44 MB floppy disk!
The significant reduction in available space you’re seeing on your encrypted FAT12 container is primarily due to the overhead of VeraCrypt volume headers:
Each VeraCrypt volume allocates 64 KB for a primary header and 64 KB for a backup header, totaling 128 KB. Most of this space is reserved and filled with random data, allowing for future updates to the VeraCrypt format without needing to recreate volumes.
Additionally, VeraCrypt always reserves another 128 KB for potential hidden volume headers (primary and backup) even if you don’t create a hidden volume. This is done to ensure plausible deniability with the space also filled with random data when not used.
In total, 256 KB of your floppy disk’s capacity is used for headers alone which explains the reduction of usable space by around 299 KB.
Unfortunately, there’s no way to reduce this overhead with the current VeraCrypt format.
There is a feature on the TODO list to allow specifying header offsets dynamically, which could include setting the offset of the data area. This feature would enable a reduction in the size of stored headers. However, implementing this requires significant work and there’s no timetable for when it might be addressed.
For now, you’ll need to work within these limitations.
I have managed to make a VeraCrypt Traveler Disk fit on a 1.44 MB 3.5¨ floppy disk with 34 KB to spare using strong self-extracting compression.
Now I want to minimize the overhead of the encrypted FAT container created on another second floppy disk.
Allocating the full microfloppy capacity of 1.44 MB, the mounted VeraCrypt volume has a capacity reduction of -299 KB. This leaves less than 80 % of usable FAT12 space remaining on the disk.
Is there any way to increase the portion of free space? Where did it go?
I need to use no more than two 3.5¨ floppy disks in total or else there is unnecessary hassle and an additional surcharge mailing fee due to the extra weight of an additional disk when sending sensitive files/data off-line. This is of course not an issue when burning CD/DVDs, however they aren't as volatile and are more difficult to erase/destroy after use.
Last edit: 2024-08-13
You’ve done an impressive job fitting a VeraCrypt Traveler Disk onto a 1.44 MB floppy disk!
The significant reduction in available space you’re seeing on your encrypted FAT12 container is primarily due to the overhead of VeraCrypt volume headers:
Each VeraCrypt volume allocates 64 KB for a primary header and 64 KB for a backup header, totaling 128 KB. Most of this space is reserved and filled with random data, allowing for future updates to the VeraCrypt format without needing to recreate volumes.
Additionally, VeraCrypt always reserves another 128 KB for potential hidden volume headers (primary and backup) even if you don’t create a hidden volume. This is done to ensure plausible deniability with the space also filled with random data when not used.
In total, 256 KB of your floppy disk’s capacity is used for headers alone which explains the reduction of usable space by around 299 KB.
Unfortunately, there’s no way to reduce this overhead with the current VeraCrypt format.
There is a feature on the TODO list to allow specifying header offsets dynamically, which could include setting the offset of the data area. This feature would enable a reduction in the size of stored headers. However, implementing this requires significant work and there’s no timetable for when it might be addressed.
For now, you’ll need to work within these limitations.
For more details, you can refer to the VeraCrypt Volume Format Specification.
Last edit: Mounir IDRASSI 2024-08-13