10.1.5 - Digital Certificates and PKI

Flashcards about Digital Certificates and PKI

When you want others to send you confidential messages, what do you provide?

You give them your public key to use to encrypt the message.

What key can decrypt a message encrypted with your public key?

Only your private key.

When you want to authenticate yourself to others, what do you create?

Creates a signature using your private key.

What do others use your public key for when you want to authenticate?

Validate the signature.

What protocol can be used with smart cards?

A protocol such as Kerberos can be used with smart cards.

What problem does public key cryptography or asymmetric encryption solve?

It solves the problem of distributing encryption keys when you want to communicate securely with others, authenticate a message, or authenticate yourself to an access control system.

What should happen to the private key in asymmetric encryption?

Remains a secret that only you know.

What is the relationship between the private key and the public key in asymmetric encryption?

Cannot be derived from the public key.

How is a public key typically used rather than encrypting the whole message?

Encrypt a symmetric encryption key for use in a single session and exchange it securely.

What type of cipher is used when the key can perform both encryption and decryption?

The same key can perform both encryption and decryption.

What is the basic problem with public key cryptography?

Proving the identity of the owner of a public key.

What is the aim of public key infrastructure (PKI)?

To prove that the owners of public keys are who they say they are.

Under PKI, what should anyone distributing public keys obtain?

Obtain a digital certificate.

What does a certificate authority (CA) do?

Guarantees the validity of the certificate.

What is a digital certificate essentially?

A wrapper for a subject's (or end entity's) public key.

Give an example of when a self-signed certifcate can be used?

The web administrative interfaces of SOHO routers are often only protected by a self-signed certificate.

When shouldn't self-signed certificates be used?

They should not be used to protect critical hosts and applications.