How to encrypt/decrypt a file with a passphrase | key-file
Why we need to encrypt file
File encryption is important for several reasons:
Protection against loss or theft: If a device such as a laptop or mobile device is lost or stolen, file encryption protects against the threat of someone being able to read sensitive data off of the device.
Data Protection: Encryption helps protect your sensitive data from unauthorized access.
Ransomware Protection: Encrypting your files is a critical part of your defense against cybercriminal attacks, including ransomware.
Secure file sharing: Encryption enables secure file sharing. When you transfer files between devices or over the Internet, encryption ensures that your files remain secure in transit.
When a file is encrypted, anyone without the correct decryption key won't be able to read anything substantial,they can only see scrambled nonsense.
How to encrypt/decrypt a file with a passphrase | key-file
We will use a simple, modern and secure file encryption tool called age.
Encrypt/Decrypt a File with a Passphrase
First let's encrypt a file
age -p -o yourfile.age yourfile
# You will see hints that let you enter the same passphrase twice,such as 'hello-age':
# Enter passphrase (leave empty to autogenerate a secure one):
# Confirm passphrase:
Do you see the encrypted file yourfile.age?
Now let's decrypt it
age -d -o yourfile2 yourfile.age
# You will see hints to enter passphrase:
# Enter passphrase:
You should see the decrypted file yourfile2, check to see if it is the same as yourfile.
Encrypt/Decrypt a File with a key-file
First let's create the key file:
age-keygen -o key-private.txt
# This will create the key-private.txt and print out the public key
# Public key: age1v3uzdzzwfzlrh5yg7445lgr4d2xcux0jfh3drvsx8jrqtfmjavhqc845g5
age-keygen -y -o key-public.txt key-private.txt
# This will create the key-public.txt
Let's encrypt a file
age -R key-public.txt -o yourfile3.age yourfile
Do you see the encrypted file yourfile3.age?
Now let's decrypt the file
age -d -i key-private.txt -o yourfile4 yourfile3.age
You should see the decrypted file yourfile4, check to see if it is the same as yourfile.
Why not 7Z/Zip?
They don't support encryption with key-file(asymmetric encryption).
Why not GPG(GNU Privacy Guard)?
It's too complex for normal users.