Finney Attack

• A kind of Double Spend attack
• From this post by FlatOutCrypto (14-6-2018):

"The Finney attack relies on the attacker having a headstart

Named after Hal Finney following his description of it in 2011, a Finney attack involves an attacker mining blocks in which they include txs from and to themselves. The next time they mine a block they would delay publishing it, instead creating a tx to a merchant in exchange for immediately rendered services without waiting for blockchain confirmations. As soon as the goods are released the attacker would publish their block. This then becomes the legitimate tx, and the merchant would find their tx invalidated. The attacker ends up with both goods and original BTC."