First :
What type of encryption is used when encrypting using p7zip ? And what is keysize etc ?
Second:
If i have a 2GB text file and encrypt and split the file into two 1 GB compressed files. Is it possible when having the key to decrypt the first 1GB file and read a part of the 2GB document ?
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for 7z:
1) aes-256-cbc + 512 KIterations of SHA-256 from text password for key generation.
2) it's possible, but can be difficult. 8-bytes random IV for aes-cbc is stored at the end of archive (second volume in your case).
for zip format, 7-zip can use Winzip's aes-256.
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Hi,
I have two interesting questions.
First :
What type of encryption is used when encrypting using p7zip ? And what is keysize etc ?
Second:
If i have a 2GB text file and encrypt and split the file into two 1 GB compressed files. Is it possible when having the key to decrypt the first 1GB file and read a part of the 2GB document ?
for 7z:
1) aes-256-cbc + 512 KIterations of SHA-256 from text password for key generation.
2) it's possible, but can be difficult. 8-bytes random IV for aes-cbc is stored at the end of archive (second volume in your case).
for zip format, 7-zip can use Winzip's aes-256.
Thanks Igor for the fast response ! I was wondering about this for quite some time :)