AES vs RSA vs PGP for Text Encryption: Plain-English Comparison

When someone wants to encrypt text, they encounter three names most often: AES, RSA, and PGP. They're related but serve different purposes, and using the wrong one for your use case creates either unnecessary complexity or actual security problems. This comparison explains what each is, when to use it, and why AES-256 is the practical choice for most text encryption needs.

AES-256: The Standard for Symmetric Text Encryption

AES (Advanced Encryption Standard) is a symmetric cipher — the same key (password) encrypts and decrypts. AES-256 means a 256-bit key, the longest and strongest variant.

How it works for text:

1. You have text and a password
2. PBKDF2 derives a 256-bit key from your password + a random salt
3. AES-256-GCM encrypts the text using the derived key and a random IV
4. The output is base64-encoded for easy text handling

Best for:

• Encrypting text with a shared password
• Personal notes you want to protect
• Sending encrypted text to someone who knows the password
• File encryption (via 7-Zip, VeraCrypt, etc.)
• Any use case where both parties share a password

Limitation: Both parties need the password. Sharing the password securely is the challenge — it must be communicated through a separate secure channel.

RSA: Asymmetric Encryption — No Shared Password Required

RSA is an asymmetric cipher — it uses a public/private key pair. Anyone can encrypt with your public key; only you can decrypt with your private key.

How it works:

1. You generate a key pair: a public key (share freely) and a private key (keep secret)
2. Someone who wants to send you encrypted text uses your public key to encrypt it
3. Only your private key can decrypt it

Best for:

• Secure communication where you can't share a password in advance
• Digital signatures (proving authorship)
• Key exchange (used to establish a shared secret that AES then uses)

Limitations for everyday text encryption:

• Key pair setup required — you need to generate and manage keys
• The recipient needs your public key
• RSA directly on large text is slow and impractical — in practice, RSA encrypts an AES key, which then encrypts the text (hybrid encryption)
• Significantly more setup than password-based AES

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PGP: A System That Combines RSA and AES

PGP (Pretty Good Privacy, now OpenPGP standard) is not a cipher — it's a system that uses RSA and AES together:

1. Generate a random AES session key
2. Encrypt the message with that AES session key
3. Encrypt the session key with the recipient's RSA public key
4. Send both together as the PGP message

This gives you the security of RSA key exchange (no shared password) with the efficiency of AES encryption (fast for any message size).

PGP is used for:

• Encrypted email (ProtonMail, encrypted Gmail, S/MIME)
• Software package signing
• Secure file sharing between parties who've exchanged public keys

PGP is overkill when:

• You want to encrypt a note for yourself
• You need to quickly share an encrypted message with someone who knows your password
• You don't want the setup complexity of key management

AES vs RSA vs PGP: Side-by-Side Comparison

Feature	AES-256	RSA	PGP
Type	Symmetric	Asymmetric	Hybrid (RSA + AES)
Key required	Password	Public/Private keypair	Public/Private keypair
Setup complexity	Minimal	Moderate	High
Recipient needs	Same password	Your public key	Keyring software + your key
Good for personal notes	Yes	Overkill	Overkill
Good for email encryption	If both share password	Via PGP/S-MIME	Yes (standard)
Browser-based tool available	Yes	Rarely	Yes (Keybase, Mailvelope)
Encryption speed	Very fast	Slow	Fast (AES for content)

Decision Guide: When to Use AES, RSA, or PGP

Use AES-256 (browser-based or local) when:

• You want to encrypt text for yourself or to share with someone who can receive a password
• You want quick, no-setup encryption
• You're protecting notes, credentials, or one-off sensitive messages

Use PGP when:

• You need ongoing encrypted email with people who have PGP keys
• You're a journalist, security professional, or developer who needs established key infrastructure
• You want to sign messages/files to prove authorship

Use RSA directly (rare for text) when:

• You're implementing a key exchange protocol
• You need to encrypt a short piece of data (like an AES key) for a specific recipient's public key
• Building a system that requires asymmetric encryption at a protocol level

For 90% of "I need to encrypt some text" use cases, AES-256-GCM with a strong password is the right, fast, low-overhead answer. PGP is powerful but rarely necessary for personal text encryption.

Frequently Asked Questions

Is AES-256 more secure than RSA?

They're not directly comparable — they solve different problems. AES-256 is symmetric (shared key) and extremely fast. RSA is asymmetric (public/private keys) and used for key exchange and signatures. AES-256-GCM and RSA-4096 are both considered computationally unbreakable with correct implementation. "More secure" depends on the use case and how the keys are managed.

Can I use PGP to encrypt a text message for a friend?

Yes, but it requires setup: you need a PGP key pair, your friend needs a key pair, you need to exchange public keys, and both need PGP-compatible software (Kleopatra, GPG, Mailvelope). For a quick encrypted message where you can share a password, AES-256 is far simpler.

Does ProtonMail use PGP or AES?

Both. ProtonMail uses PGP for end-to-end encryption between ProtonMail users and external PGP users. For message storage, AES-256 is used. This is the hybrid approach PGP is based on: asymmetric (RSA within PGP) for key exchange, symmetric (AES) for content encryption.

Is RSA still secure in 2026?

RSA with 2048+ bit keys is still considered secure against classical computers. However, RSA is vulnerable to quantum computers (Shor's algorithm). NIST post-quantum cryptography standards are being finalized. For long-term sensitive data, post-quantum algorithms may eventually be preferred. For current use, RSA-2048 or RSA-4096 remains secure.