L25. Compare the properties of symmetric vs asymmetric cryptography

Question 1

What is cryptography used for?

Answer 1

Securing communications

Question 2

What are the two types of cryptographical algorithms?

Answer 2

Symmetric and asymmetric

Question 3

How does symmetric cryptography work?

Answer 3

Symmetric cryptography, also known as secret-key or private-key cryptography, uses a single key for both encryption and decryption. The same key must be shared between the sender and the receiver.

Question 4

What are the advantages of symmetric cryptography?

Answer 4

1. Generally faster than asymmetric algorithms; suitable for real-time applications
2. Require less computational power, making them suitable for encrypting large amounts of data quickly
3. The use of a single key simplifies the encryption and decryption processes.

Question 5

What is the main challenge of symmetric cryptography?

Answer 5

The secure distribution and management of keys. If the key is intercepted or disclosed, the security of the communication is compromised. Securely sharing the key between parties is problematic, especially over untrusted networks.

Question 6

What is another disadvantage of symmetric cryptography, besides secure distribution of keys?

Answer 6

Scalability – in a network with many users, the number of keys required grows exponentially, complicating key management

Question 7

What are examples of symmetric encryption algorithms?

Answer 7

AES, DES, and Blowfish/Twofish

Question 8

Name two use cases for symmetric encryption

Answer 8

1. Bulk Data Encryption: Due to their speed, symmetric algorithms are often used for encrypting large volumes of data, such as in file encryption or disk encryption.
2. Network Security: Protocols like SSL/TLS and VPNs often use symmetric encryption for the actual data transfer after establishing a secure connection with asymmetric encryption.

Question 9

How does assymetric cryptography work?

Answer 9

Asymmetric cryptography, also known as public-key cryptography, uses a pair of keys: a public key for encryption and a private key for decryption. The public key is shared openly, while the private key remains confidential.

Question 10

Why is assymetric cryptography more secure?

Answer 10

The security of asymmetric algorithms is based on mathematical problems that are computationally infeasible to solve, such as factoring large prime numbers or computing discrete logarithms.

Question 11

What is a disadvantage of assymetric cryptography?

Answer 11

Asymmetric cryptographic operations are more computationally intensive than symmetric ones, making them slower, particularly for large data sets.

Question 12

Name two examples of assymetric cryptography algorithms

Answer 12

RSA and ECC

Question 13

Name three use cases for assymetric cryptography

Answer 13

1. Secure exchange of symmetric keys over an insecure channel. Once the symmetric key is shared, it is used for faster bulk data encryption.
2. Creation of digital signatures, which verify the authenticity and integrity of a message or document.
3. Protocols such as SSL/TLS use asymmetric cryptography to establish a secure connection before switching to symmetric encryption for data transfer.

Question 14

What are two advantages of assymetric cryptography?

Answer 14

1. It simplifies the process of establishing secure communications, because the public key can be freely distributed without compromising security
2. Asymmetric cryptography scales better in environments with many users, as each user needs only a single key pair.

Question 15

Name two disadvantages of assymetric cryptography

Answer 15

1. Performance: Slower encryption and decryption processes make asymmetric cryptography less suitable for real-time or large-scale data encryption.
2. Complexity: Asymmetric cryptography involves more complex algorithms and key management practices

Question 16

Compare symmetric and assymetric cryptography

Answer 16

Symmetric cryptography: Fast and efficient for encrypting large amounts of data, but faces challenges in key distribution and scalability

Asymmetric cryptography: Slower and more computationally demanding, but offers enhanced security and simpler key management for secure communications and digital signatures

Question 17

What is a common example of how symmetric and assymetric cryptography are used together?

Answer 17

Assymetric cryptography is often used to encrypt symmetric cryptography keys in order to securely exchange them