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What is GPG encrypt file?
The GNU Privacy Guard (GPG or gpg) tool is a native/baseos security tool for encrypting files. According to the gpg man page: gpg is the OpenPGP (Pretty Good Privacy) part of the GNU Privacy Guard (GnuPG). It is a tool to provide digital encryption and signing services using the OpenPGP standard.
What is GPG recipient?
With an –encrypt-to key designated in the Options file, GPG automatically encrypts messages and files to the public keys of the recipients you specify with the –recipient option as well as your own public key. The result: both you and your recipients will be able to decrypt the files or messages.
How does GPG encrypt files with multiple keys?
GPG encrypts the file once with a symmetric key, then places a header identifying the target keypair and an encrypted version of the symmetric key. […] When encrypted to multiple recipients, this header is placed multiple times providing a uniquely encrypted version of the same symmetric key for each recipient.
How is GPG file size with multiple recipients explained?
There is a question on Information Security, GPG File size with multiple recipients?, that explain the encryption mechanism: GPG encrypts the file once with a symmetric key, then places a header identifying the target keypair and an encrypted version of the symmetric key.
How is the session key encrypted in GnuPG?
GnuPG and PGP clients in general usually encrypt the actual data with a symmetric key called a “session key”. The session key is then encrypted with each “recipient key” (i.e. the ones you specify with -r/–recipient). This is sometimes referred to as a hybrid cipher.
What kind of AES key does GnuPG use?
Right now, I believe GnuPG by default uses an 256 bit session keys and AES to encrypt the plaintext data to that AES-256 session key, and your recipient keys are your RSA/DSA/ECDSA/etc. assymetric key in this case.