Written: 20th January 2000
Last updated: 22nd January 2000
This one's more of a warning than an outright flaw in seNTry 2020.
When a seNTry 2020 volume is created, it's .raw file consists of nothing but 0x00's. This can lead to a potential security problem by allowing an attacker to gain an idea of how much data is stored within the seNTry volume/the amount of use the volume has had, by simply examining it and noting how many blocks towards the end of the drive are full of 0x00's.
Writing data to the encrypted drive only overwrites those areas of the volume that are required to store the data (as per a normal drive). This means that the ".raw" file will always contain 0x00's, unless encrypted information has been written to it.
Create a new seNTry 2020 volume, and examine the resultant ".raw" file with a hex editor; it will consist of nothing but 0x00's (decimal 0).
Format the volume, and then check it again. There is very little difference, except at the start of the volume.
Workaround: This "leak" can be prevented by mounting the volume and then running an unused disk space shredder (see Disk and File Shredders: A Comparison) on the encrypted drive (one pass of random data should be sufficient). During the shred process, the data written to the disk will be encrypted and effectively replace the original 0x00's mentioned with what appears to be purely random data.
Please see also seNTry 2020 Volume Files Are Excessivly Large
Email me at: sdean12@mailcity.com
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