GPG (GnuPG) is a free and complete implementation of PGP (pretty good privacy). It is a tool used for encrypting, decrypting, and signing messages (or many forms of data). Once the decryption is finished you will see a message. If the encrypted file was also signed GPGServices will automatically verify that signature and also display the result of that. The decrypted file will be right next to the encrypted file, that is in the same folder as the encrypted file.

• Verify Message Signature With Gpgtools For Mac

A digital signature certifies and timestamps a document. If the document is subsequently modified in any way, a verification of the signature will fail. A digital signature can serve the same purpose as a hand-written signature with the additional benefit of being tamper-resistant.

The GnuPG source distribution, for example, is signed so that users can verify that the source code has not been modified since it was packaged. Creating and verifying signatures uses the public/private keypair in an operation different from encryption and decryption.

A signature is created using the private key of the signer. The signature is verified using the corresponding public key. For example, Alice would use her own private key to digitally sign her latest submission to the Journal of Inorganic Chemistry. The associate editor handling her submission would use Alice's public key to check the signature to verify that the submission indeed came from Alice and that it had not been modified since Alice sent it. A consequence of using digital signatures is that it is difficult to deny that you made a digital signature since that would imply your private key had been compromised.

The command-line option is used to make a digital signature. The document to sign is input, and the signed document is output. Alice% gpg --output doc.sig --sign doc You need a passphrase to unlock the private key for user: 'Alice (Judge) ' 1024-bit DSA key, ID BB7576AC, created 1999-06-04 Enter passphrase: The document is compressed before signed, and the output is in binary format.

Verify Message Signature With Gpgtools For Mac

Given a signed document, you can either check the signature or check the signature and recover the original document. To check the signature use the option. To verify the signature and extract the document use the --decrypt option. The signed document to verify and recover is input and the recovered document is output. Blake% gpg --output doc --decrypt doc.sig gpg: Signature made Fri Jun 4 12: CDT using DSA key ID BB7576AC gpg: Good signature from 'Alice (Judge) '. A common use of digital signatures is to sign usenet postings or email messages.

In such situations it is undesirable to compress the document while signing it. The option causes the document to be wrapped in an ASCII-armored signature but otherwise does not modify the document. Alice% gpg --clearsign doc You need a passphrase to unlock the secret key for user: 'Alice (Judge) ' 1024-bit DSA key, ID BB7576AC, created 1999-06-04 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 [.] -----BEGIN PGP SIGNATURE----- Version: GnuPG v0.9.7 (GNU/Linux) Comment: For info see iEYEARECAAYFAjdYCQoACgkQJ9S6ULt1dqz6IwCfQ7wP6i/i8HhbcOSKF4ELyQB1 oCoAoOuqpRqEzr4kOkQqHRLE/b8/Rw2k =y6kj -----END PGP SIGNATURE. Usb turntables for mac. A signed document has limited usefulness. Other users must recover the original document from the signed version, and even with clearsigned documents, the signed document must be edited to recover the original.

Therefore, there is a third method for signing a document that creates a detached signature. A detached signature is created using the option. Alice% gpg --output doc.sig --detach-sig doc You need a passphrase to unlock the secret key for user: 'Alice (Judge) ' 1024-bit DSA key, ID BB7576AC, created 1999-06-04 Enter passphrase: Both the document and detached signature are needed to verify the signature. The --verify option can be to check the signature. Blake% gpg --verify doc.sig doc gpg: Signature made Fri Jun 4 12: CDT using DSA key ID BB7576AC gpg: Good signature from 'Alice (Judge) '.