ED25519 or RSA which one is better (2024)

FAQs

Which is better RSA or ED25519? ›

ED25519 is generally more efficient than RSA in terms of key size, computation, and memory. The key size of ED25519 is only 256 bits, while the key size of RSA is typically at least 2048 bits. This means that ED25519 requires less memory and computation to generate and verify signatures or encrypt and decrypt messages.

An ECC key is more secure than an RSA or DSA key of the same size.

To generate a robust SSH key, you have two main options: ED25519 and RSA. Both have their advantages, but ED25519 is generally recommended for its security and performance benefits.

1) Robust Security: The Ed25519 algorithm is based on elliptic curve cryptography (ECC), providing a high level of security with a 128-bit security level. It offers strong resistance against brute force attacks, making it highly suitable for protecting your remote access credentials.

AES 256-bit encryption is the strongest and most robust encryption standard that is commercially available today. While it is theoretically true that AES 256-bit encryption is harder to crack than AES 128-bit encryption, AES 128-bit encryption has never been cracked.

Microsoft has announced its intention to deprecate RSA encryption keys shorter than 2048 bits for the Windows Transport Layer Security (TLS). The move is expected to improve security levels for Microsoft products. Cybersecurity experts consider 2048-bit encryption keys to be safe at least till 2030.

RSA's public/private key pair creation method is susceptible to factorization attacks. In a factorization attack, an attacker impersonates a key owner and can get the private key for the pairing. This allows attackers to decrypt sensitive data and bypass a system's security.

RSA encryption is only secure if no one can discover the prime numbers p and q from their product n. However, if the prime numbers are too close to each other or are not random and big enough, attackers can factor them, and then it takes little to expose the private key.

Based on elliptic curve cryptography (ECC), the Ed25519 algorithm provides a high level of security with a 128-bit security level.

Ed25519 is intended to provide attack resistance comparable to quality 128-bit symmetric ciphers. Public keys are 256 bits long and signatures are 512 bits long.

What is the difference between Ed25519 and Ed448? ›

> Ed25519 is one of the two digital signature algorithms today that use the EdDSA algorithm framework. The other is Ed448, which targets a higher security level (224-bit vs 128-bit) but is also slower and uses SHAKE256 (which is overkill and not great for performance).

We strongly recommend using only the ed25519 algorithm (an ECDSA variant). It is the most secure SSH key type widely available, and is very well supported in the majority of systems. If you are using an client or server without ed25519 support, you should consider upgrading where possible.

An ED25519 key pair consists of a private key and a corresponding public key. The private key is used to generate digital signatures, while the public key is used to verify the signatures. The ED25519 algorithm is based on the elliptic curve defined over the prime field of 2²⁵⁵-19.

Ed25519 is very vulnerable to quantum computers, in that quantum computers are exponentially faster at solving this, and even require less qubits than RSA to break.

Unfortunately it cannot be done because ED25519 and RSA are completely different types of keys. You cannot convert between them.

Key Takeaways

Microsoft is discontinuing Windows RSA keys shorter than 2048 bits to encourage the adoption of more robust encryption techniques for server authentication. Since 2013, internet standards and regulatory bodies have prohibited using 1024-bit keys, recommending 2048 bits or longer RSA keys.

RSA is universally supported among SSH clients while EdDSA performs much faster and provides the same level of security with significantly smaller keys.

The opposite key from the one used to encrypt a message is used to decrypt it. This attribute is one reason why RSA has become the most widely used asymmetric algorithm: It provides a method to assure the confidentiality, integrity, authenticity, and non-repudiation of electronic communications and data storage.