Cryptography

HowTo : Create a Password Protected ZIP File in Linux

How to encrypt and decrypt a password protected ZIP file from the Linux command line.

Removing EXIF Data From Images and Photos in Linux

How to read and then remove all EXIF metadata from your images and photos, using Linux command line utility, named ExifTool.

Installing "John the Ripper" - The Password Cracker

"John the Ripper" - is a fast password cracker. Its primary purpose is to detect weak Unix passwords.

Most likely you do not need to install "John the Ripper" system-wide.

Instead, after you extract the distribution archive and possibly compile the source code (see below), you may simply enter the "run" directory and invoke John from there.

HowTo : Identify Hash Type

There are two main things, that can help to identify hash type :

  • The length of the hash (each hash function has a specific output length);
  • The alphabet used (are all english letters? numbers 0-9 and A-F so hex? what special characters are there if any?).

There is a cool script, named "Hash Identifier". The name pretty much describes it.