What is the difference between symmetric and asymmetric encryption?
Theme: Network Security Role: Network Engineer Function: Technology
Interview Question for Network Engineer: See sample answers, motivations & red flags for this common interview question. About Network Engineer: Designs and maintains computer networks. This role falls within the Technology function of a firm. See other interview questions & further information for this role here
Sample Answer
Example response for question delving into Network Security with the key points that need to be covered in an effective response. Customize this to your own experience with concrete examples and evidence
- Definition of symmetric encryption: Symmetric encryption is a method where the same key is used for both encryption and decryption. It is also known as secret key encryption
- Definition of asymmetric encryption: Asymmetric encryption, also called public key encryption, uses a pair of keys - a public key for encryption and a private key for decryption
- Key generation: In symmetric encryption, a single key is generated and shared between the sender and receiver. In asymmetric encryption, a key pair is generated - the public key is shared with others, while the private key is kept secret
- Security: Symmetric encryption provides faster encryption and decryption, but the same key must be securely shared between parties. Asymmetric encryption offers better security as the private key is kept secret, but it is slower
- Use cases: Symmetric encryption is commonly used for bulk data encryption, such as file or disk encryption. Asymmetric encryption is used for secure communication, digital signatures, and key exchange
- Key management: Symmetric encryption requires managing and distributing a single key. Asymmetric encryption requires managing key pairs, including securely distributing public keys and protecting private keys
- Scalability: Symmetric encryption is more scalable as it requires less computational overhead. Asymmetric encryption is less scalable due to the computational complexity of key generation and encryption
- Hybrid encryption: Hybrid encryption combines both symmetric and asymmetric encryption. It uses symmetric encryption for bulk data encryption and asymmetric encryption for securely exchanging the symmetric key
- Examples: Examples of symmetric encryption algorithms include AES and DES. Examples of asymmetric encryption algorithms include RSA and ECC
Underlying Motivations
What the Interviewer is trying to find out about you and your experiences through this question
- Technical knowledge: Assessing the candidate's understanding of encryption concepts and their ability to explain them accurately
- Problem-solving skills: Evaluating the candidate's ability to differentiate between different encryption methods and their applications in network engineering
- Critical thinking: Testing the candidate's analytical skills by assessing their ability to identify and explain the differences between symmetric and asymmetric encryption
Potential Minefields
How to avoid some common minefields when answering this question in order to not raise any red flags
- Lack of understanding: Providing incorrect or vague definitions of symmetric and asymmetric encryption
- Confusion: Mixing up the concepts or using incorrect terminology while explaining the differences
- Incomplete answer: Failing to mention key differences such as key distribution, speed, and usage scenarios
- Lack of practical knowledge: Inability to provide real-world examples or use cases for each type of encryption
- Overconfidence: Being overly confident or dismissive about the importance of encryption in network security