GPG encrypt a file with only a passphrase (no key storage needed)

Question

Is there a GPG encryption mode that does not requires to have a specific public key stored and requires only one passphrase to be decrypted?

It would make the decryption possible on any machine if the passphrase is known.

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PS:

I don't want to use openssl since I cannot do in place encryption easily.

In gpg

  cat file | gpg -e >  file

is encrypting the file.

Whereas

cat file | openssl enc -des3   >  file

produces an empty file.

Solution

What you want is called symmetric encryption -- where the same key is used for both encryption and decryption -- and yes, GnuPG can do it.

Use --symmetric or -c instead of -er RECIPIENT.

PS: You can combine the two modes so that a file can be decrypted by either the symmetric passphrase or by any of the RECIPIENT private keys.

Comments

[Videonauth]

I don't think this is possible, pgp or Gnupgp are using two key encryption, so you would always need your private key in whatever environment you trying to decrypt and at least would need the public one for encryption.

[user123456]

I guess a passphrase protected private key uploaded on server would make it.

[addicted]

How do you combine the symmetric and asymmetric mode?

[Penguin9]

How do you combine the symmetric and asymmetric mode?

[Kevin Detrain]

@addicted @Penguin9 I guess I thought it was obvious what "combine these two modes" meant... You can do this simply by using all 3 options, e.g., gpg -c -e -r RECIPIENT.