# Quiz 3 Which of the following statements about hash functions is true? (Choose all that apply) **Add answers and select the correct ones** * [x] Hash functions are not reversible * [x] Hash functions produce a fixed-length output * [ ] Hash functions preserve input data * [ ] Hash functions are free from collision risks \ **Note to learners** Hash functions are a one-way function that does not need to be reversed, and they produce a fixed-length output in clear text. To learn more about it, you can follow the course [What are Hash functions?](https://bsvblockchain.360learning.com/course/play/68b55339580a65662452b269) --- # 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-3.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.