OpenPGP Encryption: Encrypt and Sign
Encrypt files and messages with OpenPGP — key generation, public key encryption, and digital signatures.
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Tags: OpenPGP encryption, PGP encrypt online, GPG file encryption
OpenPGP Encryption: Encrypt and Sign OpenPGP is the standard for asymmetric encryption and digital signing. It protects data in transit and at rest, and provides non-repudiation — a signed message proves it came from the key holder. This guide covers key generation, encrypting and decrypting files and messages, digital signatures, and the openpgp.js API for browser-based implementations. OpenPGP standard (RFC 4880) has been in use since 1997 and secures communications for 500+ million users. --- How OpenPGP Works? OpenPGP uses hybrid encryption: asymmetric cryptography for key exchange, symmetric cryptography for the actual data. The encryption flow: Generate a random session key (typically AES-256) Encrypt the session key with the recipient's public key (RSA or ECDH) Encrypt the file…
Frequently Asked Questions
What is OpenPGP?
OpenPGP is an open standard for asymmetric encryption and digital signing, defined in RFC 4880 (and updated in RFC 9580). It uses public-key cryptography: each user has a public key (shareable) and a private key (kept secret). Files encrypted with a public key can only be decrypted by the corresponding private key. GPG (GnuPG) is the most widely used OpenPGP implementation.
How do I encrypt a file with PGP?
Obtain the recipient's public key. In GPG: `gpg --import recipient_public.asc`, then `gpg --encrypt --recipient recipient@example.com file.txt`. This produces `file.txt.gpg`. Alternatively, use the browser-based OpenPGP Encrypt tool which runs entirely in your browser using the openpgp.js library. The recipient decrypts with their private key.
What is the difference between OpenPGP and GPG?
OpenPGP is the standard (RFC 4880); GPG (GnuPG) is the reference open-source implementation. Other implementations include the JavaScript library openpgp.js, BouncyCastle for Java, and OpenPGP.net for .NET. They are all interoperable as long as they implement the same standard revision.
How do I share my public PGP key?
Export your public key as ASCII armor with `gpg --armor --export your@email.com > public.asc`. You can then post this file on your website, upload it to a keyserver (keys.openpgp.org, pgp.mit.edu), or distribute via Web Key Directory (WKD) at `https://yoursite.com/.well-known/openpgpkey/`.
How do I encrypt email with PGP?
For automated email encryption, use a client that supports OpenPGP: Thunderbird with its built-in OpenPGP support (Enigmail is now integrated), ProtonMail (uses PGP natively), or Fastmail (OpenPGP plugin). For the simplest approach, encrypt the message body using GPG or the browser-based tool and paste the armored ciphertext into any email client.
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