Blockchain Security: How Blockchains Protect Data and Where They Still Fail

Blockchains are among the hardest databases ever built to alter, yet attackers stole about $3.4 billion in crypto in 2025, according to Chainalysis. Both facts hold because blockchain security works on two separate levels. The ledger itself, protected by cryptography, consensus rules and thousands of independent nodes, has held up on the largest networks. The money is lost at the edges: stolen private keys, compromised signers, buggy smart contracts and cross-chain bridges.

Source: Blockchain Reporter