Final answer:
To protect its source code on a cloud platform from unauthorized access, the start-up company should use file encryption as a cyber defense measure.
Therefore, the correct answer is: option D) File encryption
Step-by-step explanation:
The start-up company concerned with maintaining the confidentiality of its source code after moving it to a cloud provider should adopt the cyber defense concept of file encryption.
Encryption is the process of converting data into a code to prevent unauthorized access, thus safeguarding sensitive information by ensuring that even if someone were to gain access to the storage location, they would be unable to interpret the source code without the proper decryption key.
This measure provides a strong layer of security to protect the company's intellectual property. Examples of file encryption include AES, RSA, Blowfish, and Twofish. These methods encrypt files in such a way that without possessing a key generated by the specific algorithm, decrypting it would be computationally impossible.