# Quiz 18 Proof-of-work in BSV requires brute-force hashing to find a solution below a difficulty target. **Select the correct response to your question** * [x] True * False \ **Note to Learners** The preimage, second preimage, and collision resistance properties of SHA-256 – and in turn HASH-256 – ensure the only way nodes are able to find a proof-of-work solution is by brute-force. To learn more about it, you can follow the course [SHA256](https://bsvblockchain.360learning.com/course/play/68bac0569f76953779e261a6) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://hub.bsvblockchain.org/higher-learning/bsv-academy/bitcoin-primitives-hash-functions/quiz-bitcoin-hash-functions/quiz-18.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.