True blockchain has five elements.
Distribution: Blockchain participants are located physically apart from each other and are connected on a network. Each participant operating a full node maintains a complete copy of a ledger that updates with new transactions as they occur.
Encryption: Blockchain uses technologies such as public and private keys to record the data in the blocks securely and semi-anonymously (participants have pseudonyms). The participants can control their identity and other personal information and share only what they need to in a transaction.
Immutability: Completed transactions are cryptographically signed, time-stamped and sequentially added to the ledger. Records cannot be corrupted or otherwise changed unless the participants agree on the need to do so.
Tokenization: Transactions and other interactions in a blockchain involve the secure exchange of value. The value comes in the form of tokens, but can represent anything from financial assets to data to physical assets. Tokens also allow participants to control their personal data, a fundamental driver of blockchain’s business case.
Decentralization: Both network information and the rules for how the network operates are maintained by nodes on the distributed network due to a consensus mechanism. In practice, decentralization means that no single entity controls all the computers or the information or dictates the rules.
Reference: Gartner
