What are the different Diffie-Hellman groups?
dh-group —Diffie-Hellman group for key establishment.
- group1 —768-bit Modular Exponential (MODP) algorithm.
- group2 —1024-bit MODP algorithm.
- group5 —1536-bit MODP algorithm.
- group14 —2048-bit MODP group.
- group15 —3072-bit MODP algorithm.
- group16 —4096-bit MODP algorithm.
What Diffie-Hellman DH group should I use?
Guidelines: If you are using encryption or authentication algorithms with a 128-bit key, use Diffie-Hellman groups 5, 14, 19, 20 or 24. If you are using encryption or authentication algorithms with a 256-bit key or higher, use Diffie-Hellman group 21.
Which Diffie-Hellman group is the strongest?
DH group 1 consists of a 768 bit key, group 2 consists of 1024 bit key, group 5 is 1536 bit key length and group 14 is 2048 bit key length. Group 14 is the strongest and most secure of the ones just mentioned, but there are other key lengths as well.
What is Diffie-Hellman group used for?
Diffie-Hellman Groups are used to determine the strength of the key used in the Diffie-Hellman key exchange process. Higher Diffie-Hellman Group numbers are more secure, but Higher Diffie-Hellman Groups require additional processing resources to compute the key.
Is Diffie-Hellman Group 14 secure?
DH with 2048 bits (group 14) has 103 bits of security That is: If a really secure VPN connection is needed, the phase 1 and phase 2 parameters should use at least Diffie-Hellman group 14 to gain 103 bits of security. Furthermore, at least AES-128 can be used, which has a security of almost 128 bits.
Is Diffie-Hellman Group 2 secure?
2—Diffie-Hellman Group 2: 1024-bit modular exponential (MODP) group. This option is no longer considered good protection. 5—Diffie-Hellman Group 5: 1536-bit MODP group. Formerly considered good protection for 128-bit keys, this option is no longer considered good protection.
Is Diffie-Hellman Group 24 safe?
Algorithms marked as AVOID do not provide an adequate security level against modern threats and should not be used to protect sensitive information. If you are using encryption or authentication algorithms with a 128-bit key, use Diffie-Hellman groups 5, 14, 19, 20 or 24.
Is Diffie-Hellman Group 5 secure?
5—Diffie-Hellman Group 5: 1536-bit MODP group. Formerly considered good protection for 128-bit keys, this option is no longer considered good protection. 14—Diffie-Hellman Group 14: 2048-bit modular exponential (MODP) group. Considered good protection for 192-bit keys.
Does VPN use Diffie-Hellman?
Diffie-Hellman (DH) is a public-key cryptography scheme that allows two parties to establish a shared secret over an insecure communications channel. DH public key cryptography is used by all major VPN gateways.
What is Diffie-Hellman Group 14?
diffie-hellman-group14-sha256. This key exchange uses the group14 (a 2048-bit MODP group) along with a SHA-2 (SHA2-256) hash. This represents the smallest Finite Field Cryptography (FFC) Diffie-Hellman (DH) key exchange method considered to be secure.
Which IKEv1 negotiation mode is faster?
IKEv1 phase 1 negotiation aims to establish the IKE SA. This process supports the main mode and aggressive mode. Main mode uses six ISAKMP messages to establish the IKE SA, but aggressive mode uses only three. Therefore, aggressive mode is faster in IKE SA establishment.