Two Security Checks Every Solana Developer Must Know to Prevent Exploits

Solana programs operate differently from traditional backends because callers supply all accounts with each instruction, meaning any account could be attacker-controlled until explicitly verified. Unlike a trusted internal database, a Solana program must treat every incoming account as potentially forged until the code proves otherwise. Most account-level vulnerabilities on Solana reduce to two fundamental checks: confirming that an account is owned by the expected program, and confirming that a required authority actually signed the transaction. Skipping the ownership check allows attackers to substitute a look-alike account with crafted data, a technique linked to some of the largest losses in Solana's history. Comparing public keys alone is insufficient for signer verification, since public keys are visible on-chain; only a valid cryptographic signature proves control of the corresponding private key.