What prevents a new node with a bigger chain to join and deceive everyone?

[t3rmin4l]

If a new node with a bigger chain than anyone's joins, wouldn't it be able to deceive everyone and everyone would accept its chain because it's the longest?

[Popeyef5]

As I understand it, this is just a toy model for a blockchain. In a more real world scenario, the data stored consists of transactions (or anything really) which is cryptographically signed by the relevant parties. So you could not create blocks containing "fake" entries because you wouldn't be able to fake the signature. Transactions not only contain information about their content, but are also signed by the relevant author