24: Asymmetric Key Encryption

Question 1

What is asymmetric key encryption ?

What is it alternatively called ?

Answer 1

It’s when there is a public and private key for encryption and decryption.

Public key cryptography.

Question 2

What is the main advantage of public key crpyto?

Answer 2

The ability to begin
a secure correspondence immediately.

Simply publish your public key needed for encryption.

Question 3

Strength and weakness of asymmetric key ?

Answer 3

Strength:

Weakness:

Suitable for short inputs.

Question 4

Strength of asymmetric key ?

Answer 4

• a public key distribution, which is needed for encryption.
• suitable for short messages
• No problem with distributing keys. Publish your public key, keep your private key secret.
• Authentication: digital signatures verify that a message is from a particular sender
• Detection of tampering: a digitally signed message cannot be modified without invalidating the signature.
• Provides non-repudiation: a digital signature is an acknowledgement of the message, so the sender can’t deny their message.

Question 5

Weakness of asymmetric key ?

Answer 5

• the computational cost for long messages.
• Public keys must be authenticated. No one can be absolutely sure that a public key belongs to a right person.
• If a private key is compromised, all messages
  can be read.
  • If a private key is lost, all messages can’t be
  decrypted.