<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  Provide an explanation of two-factor authentication. Context: Two-factor authentication adds an extra layer of security by requiring a second form of verification. Answer: [/INST]It adds an extra layer of security by requiring a second form of verification.</s>