GnuPG: Making and verifying signatures - Revision history

Unknown user at 22:26, 25 October 2022

2022-10-25T22:26:32Z

← Older revision		Revision as of 22:26, 25 October 2022
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	Sumber: https://www.gnupg.org/gph/en/manual/x135.html		Sumber: https://www.gnupg.org/gph/en/manual/x135.html

	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~~.		Digital signature mensertifikasi dan memberi timestamp pada dokumen. Jika dokumen kemudian dimodifikasi dengan cara apa pun, verifikasi tanda tangan akan gagal. Tanda tangan digital dapat memiliki tujuan yang sama dengan tanda tangan tulisan tangan dengan manfaat tambahan karena tahan terhadap kerusakan. Distribusi GnuPG source, misalnya, ditandatangani sehingga pengguna dapat memverifikasi bahwa source code belum dimodifikasi sejak di-packaged.

			Membuat dan memverifikasi digital signature menggunakan pasangan kunci publik/private dalam operasi yang berbeda dari enkripsi dan dekripsi. Digital signature dibuat menggunakan kunci private penandatangan. Tanda tangan diverifikasi menggunakan kunci publik yang sesuai. Misalnya, Alice akan menggunakan kunci private-nya sendiri untuk menandatangani kiriman terbarunya secara digital ke Journal of Anorganic Chemistry. Associate editor yang menangani kirimannya akan menggunakan kunci publik Alice untuk memeriksa tanda tangan untuk memverifikasi bahwa kiriman memang berasal dari Alice dan belum dimodifikasi sejak Alice mengirimkannya. Konsekuensi dari penggunaan tanda tangan digital adalah sulit untuk menyangkal bahwa kita telah membuat digital signature karena jika penyangkalan tersebut terjadi akan menyiratkan bahwa kunci private kita telah disusupi.


	The command-line option --sign is used to make a digital signature. The document to sign is input, and the signed document is output.		The command-line option --sign is used to make a digital signature. The document to sign is input, and the signed document is output.
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	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 --detach-sig option.		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 --detach-sig option.

			Dokumen yang ditandatangani memiliki kegunaan yang terbatas. Pengguna lain harus memulihkan dokumen asli dari versi yang ditandatangani, dan bahkan dengan dokumen yang ditandatangani, dokumen yang ditandatangani harus diedit untuk memulihkan aslinya. Oleh karena itu, ada metode ketiga untuk menandatangani dokumen yang membuat tanda tangan terpisah. Tanda tangan terpisah dibuat menggunakan opsi --detach-sig.


	alice% gpg --output doc.sig --detach-sig doc		alice% gpg --output doc.sig --detach-sig doc

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2022-10-25T22:20:40Z

Created page with "Sumber: https://www.gnupg.org/gph/en/manual/x135.html A digital signature certifies and timestamps a document. If the document is subsequently modified in any way, a verifica..."

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Sumber: https://www.gnupg.org/gph/en/manual/x135.html

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 --sign 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) <alice@cyb.org>"
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.
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 --verify 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 12:02:38 1999 CDT using DSA key ID BB7576AC
gpg: Good signature from "Alice (Judge) <alice@cyb.org>"

==Clearsigned documents==

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 --clearsign 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) <alice@cyb.org>"
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 http://www.gnupg.org

iEYEARECAAYFAjdYCQoACgkQJ9S6ULt1dqz6IwCfQ7wP6i/i8HhbcOSKF4ELyQB1
oCoAoOuqpRqEzr4kOkQqHRLE/b8/Rw2k
=y6kj
-----END PGP SIGNATURE-----

==Detached signatures==

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 --detach-sig option.

alice% gpg --output doc.sig --detach-sig doc

You need a passphrase to unlock the secret key for
user: "Alice (Judge) <alice@cyb.org>"
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 12:38:46 1999 CDT using DSA key ID BB7576AC
gpg: Good signature from "Alice (Judge) <alice@cyb.org>"

==Referensi==

* https://www.gnupg.org/gph/en/manual/x135.html