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Which encryption method is used to encrypt large files?
So we encrypt the large datafiles with good symmetric encryption and then we use strong public-key encryption to encrypt the key of symmetric encryption used to encrypt the large file and we share this encrypted Symmetric Key, and the encrypted File which can be decrypted with receiver’s private key.
What is GnuPG public key?
GnuPG uses public-key cryptography so that users may communicate securely. In a public-key system, each user has a pair of keys consisting of a private key and a public key. A user’s private key is kept secret; it need never be revealed. The public key may be given to anyone with whom the user wants to communicate.
How does GnuPG encrypt data to multiple recipients?
When encrypted to multiple recipients, this header is placed multiple times providing a uniquely encrypted version of the same symmetric key for each recipient. GnuPG and PGP clients in general usually encrypt the actual data with a symmetric key called a “session key”.
Is it possible to encrypt large files using a public key?
I’ve been reading some posts claiming that it is not practical to directly encrypt large files using a public key, and that the preferred method is to encrypt the file using a symmetric key and then encrypt this symmetric key using the public 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.
How big of a key do you need for GnuPG?
GnuPG thus only has to encrypt ~256 bits (the session key) with RSA, and can use AES to encrypt the data (as large as you want it to be!) with that session key. Intel machines even have a built in instruction, AES-NI, to do some steps of the algorithm in hardware, which makes GnuPG extra snappy at encrypting/decrypting data.