Pretty Good Privacy
PGP (Pretty Good Privacy) is an encryption program that ensures privacy and authentication for data communication. It is used for signing, encrypting, and decrypting texts, emails, files, directories, and whole disk partitions.
History
PGP was developed by Phil Zimmermann out of concern for the lack of privacy in digital communications. He aimed to provide individuals with strong encryption tools. In 1991, PGP was released to the public for free, marking the beginning of a new era in digital security.
Legal Challenges
In the early 1990s, strong encryption was classified as a weapon under U.S. export law. When PGP spread globally via the internet, Zimmermann faced a criminal investigation for “exporting munitions.”
His defense was clever: he published the PGP source code in a book. Books are protected speech. The case was dropped in 1996, and encryption export restrictions were eventually relaxed in 2000.
Key Features
- Encrypts and decrypts data to ensure secure communication
- Provides authentication to verify the identity of senders and receivers
- Generates public and private keys for secure key exchange
- Supports various encryption algorithms and hash functions
Today, PGP lives on as OpenPGP (the standard) and GPG (GNU Privacy Guard, the free implementation). When you verify a software download or sign a git commit, you’re often using GPG.
How it works
PGP uses a combination of public-key and symmetric-key to ensure secure data transmission. It generates a keypair consisting of a public key and a private key. The public key is shared with others, while the private key is kept secret. When data is encrypted, it is encrypted with the public key, and only the corresponding private key can decrypt it.
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Symmetric Key Encryption: PGP generates a unique, one-time-use session key to encrypt the message. This method is fast and efficient but requires the sender and recipient to share the same key securely.
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Asymmetric Key Encryption: PGP solves the key exchange problem with asymmetric encryption. Each user has a public key and a private key. The session key is encrypted with the recipient’s public key and can only be decrypted by the recipient’s private key.
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Digital Signatures: PGP provides authentication through digital signatures. The sender signs the message with their private key, allowing the recipient to verify the sender’s identity using the sender’s public key, ensuring the message has not been tampered with.
My public key
Fingerprint
56D5 D60B 0934 0999 199C 3750 E51B 5BF4 5F85 D160Import directly
curl https://chemaclass.com/pgp.asc | gpg --import