IT Security Stack Exchange
IT Security Stack Exchange

Questions tagged [7zip]

7-Zip is an open source file compression and archiving application. Use this tag for questions regarding this application.

7-Zip is a free and open source file compression and archiving application distributed under GNU LGPL license. By default it creates archive in .7z file extension.

Related Links

  1. 7-Zip - Website
  2. 7-Zip - Wikipedia
20 questions
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2 answers

What is the impact of the reported weak IV in 7 Zip?

It has been reported that 7 Zip generates IVs in a weak manner. What is the actual impact of this? I'm asking about historical Zip files that I've sent. I've no plans to use 7 Zip going forward until this is fixed. If I understand correctly, 7 Zip…
paj28
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1 answer

Does 7-Zip really run multiple rounds of SHA-256 when key stretching?

Recently I was testing whether I could make 7-Zip archives more bruteforce-resistant. Both someone on Wikipedia and @kelalaka on this website make the following claim: The 7z format supports encryption with the AES algorithm with a 256-bit key. The…
d33tah
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5
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1 answer

Encryption Using 7z or Zip File

I'm wondering which encrypted 7-Zip file format has better encryption: 7z with 256 AES or zip file with 256 AES? Assume that a strong password is used, then which encrypted 7zip file format has stronger encryption to encrypt info in a text file?
J. A.
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4
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4 answers

Are files encrypted with 7ZIP vulnerable to password crackers?

A client says they can't accept password-protected PDFs to put in their payroll system, so I have to send them without security. I don't want to send unsecured PDFs via e-mail because e-mail is inherently insecure. I figured a good alternative was,…
Marquizzo
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2
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1 answer

AES256 - 7zip Vs GPG

I noticed that 7zip provides an option to encrypt the contents of a folder using AES256 (Screenshot Below) and so does GPG using this command: gpgtar --output -v --encrypt --symmetric --gpg-args "--cipher-algo AES256"…
7_R3X
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2
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0 answers

Recovered a 7z password with hashcat, but it's not the right one

I am trying to recover a 7z file, but have forgotten the password. It's completely AES-256 encrypted (i.e. not even the filenames are available). Steps: Generated hash file with 7z2hashcat.pl Ran a mask attack using hashcat -a 3 -m 11600 my.hash…
Ben Owen
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2
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1 answer

Decrypting a password-protected 7z file with Delta filter fails

I have made a 7z archive using Delta filter containing a wav file and I have protected it with a password. I am running a terminal in Kali Linux. My problem is that I cannot get the password cracked using 7z2john.pl and John the Ripper. If I omit…
juhohe
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How does the "ClaimLetter#.zip" attack work?

I wonder if this is the right place to ask about the specific functioning of viruses / worms. We all receive fishy mails all the time. And generally I never click on anything, especially not attachments purporting to be quotes, letters, sipping…
Gunther Schadow
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1 answer

Military-grade encryption on Blu-ray discs?

Another thread addresses the question of what can count as "military-grade encryption." In this case, I see that CyberLink Power2Go software boasts "advanced military-grade 256-bit encryption." TechRadar clarifies that Power2Go uses AES-256. The…
Ray Woodcock
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1
vote
1 answer

Cracking Lost Password for encrypted 7z file with most characters known

I forgot password to 7z archive encrypted with AES 256. I am fairly certain of most characters however. I know password length is either 8 or 12 characters and if it is 12 I know the last 4 characters. I am certain of 1st, 4th, 5th characters. I…
gary0824
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1 answer

Can I consider files compressed with password safe at all?

A follow up to my 7,5 years old question. Back 10-15 years ago, when I wanted to send an executable file over Gmail from my PC, all I had to do was to change file's extension to some meaningless one or compress that file with a password. The…
trejder
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3 answers

Does compression level influence security of encryted 7z files?

I want to archive some GB of sensitive data. It is to be stored on an external drive that also includes non sensitive data so i don't want to encrypt the whole drive. For that purpose i want to use 7zip and the 7z file format with AES-256 encryption…
WiCloverS18
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1 answer

JohnTheRipper Advanced Mask

I have problem to construct advanced mask to crack hash of 7zip file. The password have 16 chars where are all lower, upper, decimal and !@#$%-_=+: Main information is that any char can't duplicate and I want to know how add this to cracking rules.…
AxeQuestion
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1 answer

Executing vs Extracting PE32/PE32+ executable

If you have a malicious upon execution ("running" it / double clicking on it) .exe , would extracting its contents with something like 7-Zip utility mitigate its effects? Or can it still do harm?
fibonaccipistacci
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Application to archive a file with multiple passwords

Is there an application to create an archive (e.g. 7z, zip, rar, etc) that can be accessed with multiple valid passwords? For example the password protected archive "example.7z" can be extracted using either "Passw0rd", "Passw1rd" or…
David
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