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What is GnuPG encryption key?
GPG relies on the idea of two encryption keys per person. Each person has a private key and a public key. The public key can decrypt something that was encrypted using the private key. To send a file securely, you encrypt it with your private key and the recipient’s public key.
What is subkey in cryptography?
A subkey can be used for signing or for encryption. The really useful part of subkeys is that they can be revoked independently of the primary keys, and also stored separately from them. In other words, subkeys are like a separate key pair, but automatically associated with your primary key pair.
What is PGP subkey?
A PGP key has a signing key and an encryption encryption subkey. The Master Key is designated as such, so that the key can continue to be identified by the same Key ID regardless of what additional subkeys you choose to add.
How does gpg encryption and decryption work?
It works by using a public-key cipher to share a key for the symmetric cipher. The actual message being sent is then encrypted using the key and sent to the recipient. Since symmetric key sharing is secure, the symmetric key used is different for each message sent. Hence it is sometimes called a session key.
How safe is GnuPG encryption?
Very safe! GnuPG (Gnu Privacy Guard) has been proven to be unhackable in the real world and is used by companies worldwide to encrypt sensitive information so only the encryptor and recipient can read the data. To everyone else it is unusable.
What does subkey mean?
subkey (pl. subkeys) (cryptography) A partial key. (computing, Microsoft Windows) A key located beneath another key in the registry.
How to create an encryption key in GnuPG?
If there is no additional sub-key to be created, the process can be ended by the command “save” to store the modifications to the key. An encryption key can now be created in the same way as the signing key just by selecting the “RSA (encrypt only)” key type.
Can a GnuPG key be used on a smartcard?
In order to use a GnuPG key on a smartcard or Yubikey, a GnuPG key needs to be created. This post will show you how to create a GnuPG key with sub-keys for signing, encryption and authentication. The authentication key can be used later on to authenticate via ssh as well.
Can a GnuPG authentication key be used on SSH?
The authentication key can be used later on to authenticate via ssh as well. Before the key can be generated, first you need to configure GnuPG. The following settings are suggested before creating the key. The settings contain the documentation from the official GnuPG documentation.
What’s the maximum size of a GnuPG key?
Before starting to generate the different sub-keys, verify the maximum size of keys the smartcard can store. The Yubikey NEO can store keys up to 2048 bits while the Yubikey 4 can store keys up to 4096 bits. Smartcards usually support different sizes as well like 2048, 3072 or 4096 bits.