To answer this question, you need to understand the concept of proprietary protocols and data formats.
Option A) Are unsafe because they typically rely on security by obscurity - This option is correct. Proprietary protocols and data formats are considered unsafe because they often rely on security by obscurity. This means that their security is based on the secrecy of their implementation rather than on solid cryptographic principles or widely tested security measures. This approach can make it easier for attackers to exploit vulnerabilities and gain unauthorized access.
Option B) Are unsafe because buffer overflows cannot be effectively determined by random submission of data - This option is incorrect. Buffer overflows are a type of vulnerability that can occur in any type of protocol or data format, regardless of whether it is proprietary or not. The ability to determine and mitigate buffer overflows depends on the implementation and security measures taken, rather than the proprietary nature of the protocol or format.
Option C) Are insecure because vendors do not test them - This option is incorrect. While it is possible that some vendors may not thoroughly test their proprietary protocols and data formats, it is not a general characteristic of all proprietary systems. The security of a protocol or format depends on the efforts and practices of the vendor, rather than the proprietary nature itself.
Option D) Are secure because of encryption - This option is incorrect. While encryption can provide a level of security for data transmission or storage, it does not guarantee the overall security of a proprietary protocol or data format. Security encompasses various aspects such as authentication, access control, integrity, and more, which encryption alone may not address.
The correct answer is A) Are unsafe because they typically rely on security by obscurity. This option is correct because proprietary protocols and data formats that rely on security by obscurity can be more easily exploited by attackers.