to provide encryption

to provide authentication

to provide integrity verification

to prevent DoS attacks

DH

a private key

the same public key

a different public key

Symmetric algorithms are typically hundreds to thousands of times slower than asymmetric algorithms.

Symmetric encryption algorithms are used to authenticate secure communications. Asymmetric encryption algorithms are used to repudiate messages.

Symmetric encryption algorithms are used to encrypt data. Asymmetric encryption algorithms are used to decrypt data.

Symmetric encryption algorithms use pre-shared keys. Asymmetric encryption algorithms use different keys to encrypt and decrypt data.

to provide nonrepudiation support

to support email data confidentiality

to encrypt data traffic after a VPN is established

to generate a shared key over an unsecured channel before data communications

confidentiality

authentication

integrity

nonrepudiation

confidentiality

integrity

authentication

secure key exchange

DH

confidentiality

integrity

authentication

secure key exchange

AH

IP protocol 50

ESP

DH

authentication

confidentiality

Diffie-Hellman

integrity

nonrepudiation

The length of a key will not vary between encryption algorithms.

The length of a key does not affect the degree of security.

The shorter the key, the harder it is to break.

The longer the key, the more key possibilities exist.

VPNs use dedicated physical connections to transfer data between remote users.

VPNs use logical connections to create public networks through the Internet.

VPNs use open source virtualization software to create the tunnel through the Internet.

VPNs use virtual connections to create a private network through a public network.