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- Table of Contents
- Generating a new keypair
- Exchanging keys
- Encrypting and decrypting documents
- Making and verifying signatures
- Gpg Generate Key Pair
- Generate Gpg Key Windows
- Gpg Rsa
- Gpg Generate Key Pair
- Generate Rsa Key Pair Online
GnuPG is a tool for secure communication.This chapter is a quick-start guide that covers the core functionalityof GnuPG.This includes keypair creation, exchanging and verifying keys, encryptingand decrypting documents, and authenticating documents with digitalsignatures.It does not explain in detail the concepts behind public-key cryptography,encryption, and digital signatures.This is covered in Chapter 2.It also does not explain how to use GnuPG wisely.This is covered in Chapters 3 and 4.
GnuPG uses public-key cryptography so that users may communicate securely.In a public-key system, each user has a pair of keys consisting ofa 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 tocommunicate.GnuPG uses a somewhat more sophisticated scheme in which a user hasa primary keypair and then zero or more additional subordinate keypairs.The primary and subordinate keypairs are bundled to facilitate keymanagement and the bundle can often be considered simply as one keypair.
Apr 04, 2017 To encrypt your communication, the first thing to do is to create a new keypair. GPG is able to create several types of keypairs, but a primary key must be capable of making signatures. # gpg -gen-key Please select what kind of key you want: Your selection? 1 RSA keys may be between 1024 and 4096 bits long. What keysize do you want? Jun 30, 2018 Create Your Public/Private Key Pair and Revocation Certificate. Use gpg -full-gen-key command to generate your key pair. Gpg -full-gen-key. It asks you what kind of key you want. Notice there’re four options. The default is to create a RSA public/private key pair and also a RSA signing key. Let’s hit Enter to select the default. Create a GPG Key Pair. Once you have GPG installed you’ll need to create a GPG key pair (public and private key). Create a new primary key pair: gpg -full-generate-key Select (1) RSA and RSA (default) for the type of key. Enter 4096 for the key size. Enter 1m (one month) for the expiration of your key pair. SSH keys and GnuPG (actually, OpenPGP) keys are completely different, even though both protocols can use RSA key pairs. And besides, why would you want to do it? Even if you were to use the same key material to make up your PGP key, you'd still need to distribute your key as a PGP key. May 28, 2015 This blog describes how to generate a private/public key pair using GPG version 1.4.5. The resulting public key will contain two keys, one key for signing and a subkey for encryption. This key can be used with HCM Fusion SaaS to encrypt/decrypt files as they are transferred to.
The command-line option --gen-keyis used to create a new primary keypair.GnuPG is able to create several different types of keypairs, but a primarykey must be capable of making signatures.There are therefore only three options.Option 1 actually creates two keypairs.A DSA keypair is the primary keypair usable only for making signatures.An ElGamal subordinate keypair is also created for encryption. Option 2 is similar but creates only a DSA keypair.Option 4[1] creates a single ElGamal keypair usable for both making signatures and performing encryption.In all cases it is possible to later add additional subkeys for encryptionand signing.For most users the default option is fine.
You must also choose a key size.The size of a DSA key must be between 512 and 1024 bits, and an ElGamalkey may be of any size.GnuPG, however, requires that keys be no smaller than 768 bits.Therefore, if Option 1 was chosen and you choose a keysize larger than1024 bits, the ElGamal key will have the requested size, but the DSAkey will be 1024 bits.The longer the key the more secure it is against brute-force attacks,but for almost all purposes the default keysize is adequate sinceit would be cheaper to circumvent the encryption than try to break it.Also, encryption and decryption will be slower as thekey size is increased, and a larger keysize may affect signature length.Once selected, the keysize can never be changed.
Finally, you must choose an expiration date.If Option 1 was chosen, the expiration date will be used for both theElGamal and DSA keypairs.For most users a key that does not expire is adequate.The expiration time should be chosen with care, however,since although it is possible to change the expiration date after the keyis created, it may be difficult to communicate a changeto users who have your public key.
You must provide a user ID in addition to the key parameters.The user ID is used to associate the key being created with a realperson.Only one user ID is created when a key is created, but it is possibleto create additional user IDs if you want to use the key in two ormore contexts, e.g., as an employee at work and a political activiston the side.A user ID should be created carefully since it cannot be edited afterit is created.
GnuPG needs a passphrase to protect the primary and subordinate private keys that you keep in your possession.There is no limit on the length of a passphrase, and it should becarefully chosen.From the perspective of security, the passphrase to unlock the privatekey is one of the weakest points in GnuPG (and other public-key encryption systems as well) since it is the only protection you have if another individual gets your private key.Ideally, the passphrase should not use words from a dictionary andshould mix the case of alphabetic characters as well as use non-alphabetic characters.A good passphrase is crucial to the secure use of GnuPG.
Generating a revocation certificateAfter your keypair is created you should immediately generate a revocationcertificate for the primary public key using the option--gen-revoke.If you forget your passphrase or if your private key is compromised or lost, this revocation certificate may be published to notify othersthat the public key should no longer be used.A revoked public key can still be used to verify signatures madeby you in the past, but it cannot be used to encrypt future messagesto you.It also does not affect your ability to decrypt messages sent toyou in the past if you still do have access to the private key.The argument mykey must be a keyspecifier,either the key ID of your primary keypair or any part of a user IDthat identifies your keypair.The generated certificate will be left in the filerevoke.asc.If the --output option is omitted, the result will be placed on standard output.Since the certificate is short, you may wish to print a hardcopy ofthe certificate to store somewhere safe such as your safe deposit box.The certificate should not be stored where others can access it sinceanybody can publish the revocation certificate and render thecorresponding public key useless.
Notes
[1]Option 3 is to generate an ElGamal keypair that isnot usable for making signatures.
Using gpg you can generate private and public keys that can be used to encrypt and decrypt files as explained in this example.
Gpg Generate Key Pair
Step 1: Create a new GPG key-pair
The bold items mentioned in this example are inputs from user.
Step 2: Export your public key
Step 3: Import others public key
Use –import option to import others public key.
Step 4: Send encrypted message
In this example, let us see how John can send an encrypted message to Bob.
John encrypts the input file using Bob’s public key. The example below creates a binary file.
For some reason, if John cannot send the encrypted-binary files to Bob, he can always create a ASCII-encrypted-file as shown below.
Generate Gpg Key Windows
Step 5: Read the encrypted message
Gpg Rsa
In this example, le us see how Bob can read the encrypted message from John.
Decrypt the message using your private key.
Decrypt the message using your private key.
Note: After entering the passphrase, the decrypted file will be printed to the stdout.
Gpg Generate Key Pair
Use the following command to redirect the decrypted message to a text file.
Additional GPG commands:
Generate Rsa Key Pair Online
You can list all the GPG keys as shown below.