Prelude: Ed25519
Asymmetric algorithm, also known as public-key cryptography, is a cryptographic algorithm where a secret key can be divided into two parts: a public key and a private key. Here, the public key can be given to any party, trusted or not, while the private key must be kept secret. This algorithm thrives in two primary use cases: confidentiality and authentication.
An asymmetric algorithm allows any party who has access to the public key to sign a message, and the party with the private key corresponding to the public key can verify the message. For instance, it can be combined with PKIs to find out who holds the private key, hence providing authentication. More so, using the asymmetric algorithm allows a party holding the public key to encrypt a message, which can be decrypted by the corresponding party holding the private key, hence ensuring confidentiality.
ED25519 is an elliptic curved-based algorithm that is related to the asymmetric algorithm family as it follows its structure of a pair of keys: a private key and a public key. It is optimized for digital signatures, which is a core part of the asymmetric algorithm. Lastly, it uses the mathematics of elliptic curve cryptography, which is a part of the asymmetric algorithm to generate pairs of keys. The next section will go over ED25519 in detail, going over its features.
In summary, Ed25519 is known to be a good cryptographic design as it is more efficient than old algorithms such as Rivest-Shamir-Aldleman and Digitial Signature Algorithms. This makes Ed25519 suitable for high-performance systems like blockchains (Solana), where large volumes of transactions are processed frequently and swiftly. Ed25519 also provides security against cryptographic attacks such as collision attacks (two inputs are guessed randomly to produce the same hash value) and side-channel attacks (exploitation of information through branch prediction unit during the execution of cryptographic execution).
Ed25519 signatures are elliptic curve signatures, carefully engineered at several levels of design and implementation to achieve very high speeds without compromising security. Ed25519 is an elliptic curve signing algorithm using EdDSA and Curve25519
Core Features
The core features of Ed25519 are:
- Fast Signing and Key Generation: A modern 12-core 3.5GHz processor signs 436,000 messages per second, while a 2024 16-core 4.0GHz processor signs 545,000 messages per second. The key generation speed is as fast as signing.
- Secure session keys. Signatures are generated deterministically; key generation consumes new randomness, but new signatures do not.
- Collision resilience. Hash-function collisions do not break this algorithm. This adds a layer of defense against the possibility of weakness in the selected hash function.
- No secret branch conditions. Ed25519 does not perform conditional branches based on secret data; the pattern of jumps is completely predictable. This makes it immune to side-channel attacks that rely on the leakage of information through the branch prediction unit.
- Small signatures. Signatures fit into 64 bytes. These signatures are compressed versions of longer signatures; the times for compression and decompression are included in the cycle counts reported above.
- Small keys. Public keys consume only 32 bytes, which means the times for compression and decompression are reduced.
ED25519 in Solana
In Solana, Ed25519 leverages its public key cryptography for wallet management and signing transactions, where the private key signs transactions and the public key identifies the account. One of Ed25519’s core features is having a public key of only 32 bytes; this allows for the fast dissemination of data across the network due to its compact size, which contributes to Solana’s high throughput.
Furthermore, most Solana accounts use an Ed25519 public key as their address and a 64-byte private key to sign transactions. ED25519 is integral to Solana wallets like Phantom, Sollet, and Solflare, where users generate key pairs to manage their accounts and sign transactions efficiently.
Wrapping Up
In conclusion, Ed25519 is crucial to the Solana network, enhancing security while ensuring high throughput, reducing data sizes, and enabling fast transaction processing. Its efficient signing and compact key sizes play a significant role in maintaining Solana’s scalability and performance.
