Qu'est-ce qu'un Layer 2 (L2) et pourquoi est-il indispensable pour Ethereum ?

Layer 2 solutions enhance Ethereum performance by processing transactions off the main chain to reduce fees and confirmation times. Meanwhile, Bitcoin utilizes ECDSA, an elliptic curve cryptography algorithm, to provide high security with small key sizes for transaction authentication. In contrast, Monero (XMR) focuses on privacy, employing stealth addresses and ring signatures to mask senders, recipients, and transaction amounts. Together, these technologies address scalability, security, and anonymity within the diverse cryptocurrency ecosystem.