เข้ารหัสและถอดรหัส PGP

(เอกสารเป็นภาษาอังกฤษ)

What it does

This tool lets you encrypt and decrypt messages using PGP (Pretty Good Privacy) public/private key pairs, powered entirely by OpenPGP.js running in your browser. No data is sent to any server — all cryptographic operations happen client-side.

PGP uses public-key cryptography: you share your public key openly so anyone can encrypt messages meant for you, and only you can decrypt them with your corresponding private key. This is the same technology used for encrypted email (PGP/MIME), signed software releases, and secure file transfer.

The tool supports:

• Encrypt — paste a recipient’s public key and a plaintext message → get an ASCII-armored PGP ciphertext
• Decrypt — paste your private key (+ optional passphrase) and an encrypted message → get the original plaintext
• Key inspection — paste any PGP key (public or private) to see the owner’s identity, fingerprint, algorithm, and creation date

How to use it

Encrypt a message

1. Select Encrypt mode.
2. Paste the recipient’s ASCII-armored public key into the first textarea. The key info (user ID, fingerprint, algorithm) appears automatically.
3. Type or paste your plaintext message.
4. Press Encrypt message. The ASCII-armored ciphertext appears in the output — copy it with the Copy button and send it to the recipient.

Decrypt a message

1. Select Decrypt mode.
2. Paste your ASCII-armored private key.
3. If your private key is passphrase-protected, enter the passphrase.
4. Paste the encrypted message (the -----BEGIN PGP MESSAGE----- block).
5. Press Decrypt message. The original plaintext appears in the output.

Examples

Encrypting “Meeting at 3pm” for Alice:

• Recipient public key: Alice’s RSA key (fingerprint shown)
• Message: Meeting at 3pm
• Output: -----BEGIN PGP MESSAGE-----...-----END PGP MESSAGE-----

Alice decrypts with her private key + passphrase → Meeting at 3pm

Trying to decrypt with Bob’s key instead → error (the ciphertext is sealed for Alice’s key only).

Good to know

• Zero server contact. All encryption and decryption runs in your browser via OpenPGP.js. You can disconnect from the internet and the tool still works.
• ASCII armor is the standard. PGP outputs are wrapped in -----BEGIN PGP ...----- / -----END PGP ...----- blocks with

  base64base64An encoding representing binary data as 64 safe ASCII characters, so it survives transport through text-only channels. It encodes — it does not encrypt.

  -encoded content and

  checksumschecksumsA short digest computed from a block of data, compared after transfer or storage to detect corruption. Changing one bit changes the checksum.

  . This makes them safe to paste into emails, chat, or any text channel.
• Public keys are safe to share. Anyone with your public key can encrypt a message for you, but they cannot decrypt it — only your private key can do that. Think of it like a padlock you hand out; anyone can snap it shut, only you have the key.
• Protect your private key. Your private key should never be shared. If it’s passphrase-protected, an attacker needs both the key file and the passphrase to read your encrypted messages.
• Key fingerprints are unique IDs. A fingerprint (40 hex characters for RSA keys) uniquely identifies a PGP key. Always verify fingerprints with your contacts through a trusted channel to prevent key-spoofing attacks.
• Related tools: Age File Encryption (simpler file encryption with passphrases),

  Base64Base64An encoding representing binary data as 64 safe ASCII characters, so it survives transport through text-only channels. It encodes — it does not encrypt.

  Encoder (encode/decode base64 without encryption),

  HashHashA one-way function that maps data of any size to a fixed-length digest. Same input, same digest; any change, different digest; not reversible.

  Generator (create cryptographic hashes).