Final answer:
The National Security Agency (NSA) approves high-robust encryption for all classified traffic transmitted across unsecured channels.
Step-by-step explanation:
The organization that approves high-robust encryption for all classified traffic transmitted across unsecured channels is the National Security Agency (NSA). The NSA is responsible for developing encryption standards and protocols that ensure the security and confidentiality of classified information.
One example of high-robust encryption approved by the NSA is the Advanced Encryption Standard (AES). AES is widely used in government and military applications to protect sensitive data from unauthorized access.
In addition to the NSA, there are other organizations and international standards bodies that play a role in approving encryption algorithms, such as the National Institute of Standards and Technology (NIST) in the United States and the International Organization for Standardization (ISO) internationally.