While blockchain technology originally emerged as a solution to provide distributed trust within the Bitcoin network, the technology has progressed a long way since 2008. While this new architecture has many advantages, the implementation of a blockchain-based system is complex and requires a thorough review to ensure appropriate security.
Regardless of which blockchain you use, there are no avoiding key management concerns. The distributed ledger ecosystem requires each user to store and manage their own cryptographic keys. All on-chain interactions are tied to identities using signatures with private keys. As a result, the ecosystem depends heavily on the security of its keys.
More information is available about Public Key Cryptography in the Blockchain 101 Course.