Algorithm Operation Status Alternative QCR1 Mitigation
DES Encryption Avoid AES
3DES Encryption Legacy AES Short key lifetime
RC4 Encryption Avoid AES
AES-CBC-128 Encryption Acceptable AES-GCM-256
AES-CBC-192 Encryption Acceptable AES-GCM-256
AES-CBC-256 Encryption Acceptable AES-GCM-256
AES-GCM-128 Authenticated encryption3 NGE2
AES-GCM-256 Authenticated encryption NGE
DH-768 (Group 1) Key exchange Avoid DH-3072 (Group 15)
RSA-768 Encryption Avoid RSA-3072
DSA-768 Authentication Avoid DSA-3072
DH-1024 (Group 2) Key exchange Avoid DH-3072 (Group 15)
RSA-1024 Encryption Avoid RSA-3072
DSA-1024 Authentication Avoid DSA-3072
DH-2048 (Group 14) Key exchange Acceptable ECDH-256 (Group 19)
RSA-2048 Encryption Acceptable
DSA-2048 Authentication Acceptable ECDSA-256
DH-3072 (Group 15) Key exchange Acceptable ECDH-256 (Group 19)
RSA-3072 Encryption Acceptable
DSA-3072 Authentication Acceptable ECDSA-256
MD5 Integrity Avoid SHA-256
SHA-1 Integrity Legacy SHA-256
SHA-256 Integrity NGE SHA-384
SHA-384 Integrity NGE
SHA-512 Integrity NGE
HMAC-MD5 Integrity Legacy HMAC-SHA-256 Short key lifetime
HMAC-SHA-1 Integrity Acceptable HMAC-SHA-256
HMAC-SHA-256 Integrity NGE
ECDH-256 (Group 19) Key exchange Acceptable ECDH-384 (Group 20)
ECDSA-256 Authentication Acceptable ECDSA-384
ECDH-384 (Group 20) Key exchange NGE
ECDSA-384 Authentication NGE

1. QCR = quantum computer resistant.

2. NGE = next generation encryption.

3. Provides both encryption and authentication in one.

Algorithms by Operation

Key exchange

Algorithm Operation Status Alternative QCR Mitigation IOS command4 ASA command5
DH-768 (Group 1) Key exchange Avoid DH-3072 (Group 15) group 1 group 1
DH-1024 (Group 2) Key exchange Avoid DH-3072 (Group 15) group 2 group 2
DH-1536 (Group 5) Key exchange ECDH-256 (Group 19) group 5 group 5
DH-2048 (Group 14) Key exchange Acceptable ECDH-256 (Group 19) group 14 group 14
DH-3072 (Group 15) Key exchange Acceptable ECDH-256 (Group 19) group 15
DH-4096 (Group 16) Key exchange ECDH-256 (Group 19) group 16
DH-6144 (Group 17) Key exchange ECDH-256 (Group 19)
DH-8192 (Group 18) Key exchange ECDH-256 (Group 19)
ECDH-256 (Group 19) Key exchange Acceptable ECDH-384 (Group 20) group 19 group 19
ECDH-384 (Group 20) Key exchange NGE group 20 group 20
ECDH-521 (Group 21) Key exchange group 21 group 21
DH-2048/224 (Group 23) Key exchange
DH-2048/256 (Group 24) Key exchange group 24 group 24
NIST-EC224 (Group 26) Key exchange
BP-EC224 (Group 27) Key exchange
BP-EC256 (Group 28) Key exchange
BP-EC384 (Group 29) Key exchange
BP-EC512 (Group 30) Key exchange

4. under crypto isakmp policy (IKE) or crypto ike2 proposal (IKEv2)

5. under crypto ikev2 policy (IKEv2)

Encryption

Algorithm Operation Status Alternative QCR Mitigation IOS command6 IOS command7 ASA command8 ASA command9
Null Encryption Avoid AES esp-null null null
SEAL Encryption Avoid AES esp-seal
RC4 Encryption Avoid AES
RSA-768 Encryption Avoid RSA-3072
RSA-1024 Encryption Avoid RSA-3072
DES Encryption Avoid AES des esp-des des des
3DES Encryption Legacy AES Short key lifetime 3des esp-3des 3des 3des
RSA-2048 Encryption Acceptable
RSA-3072 Encryption Acceptable
AES-CBC-128 Encryption Acceptable AES-GCM-256 IKEv1: aes
IKEv2: aes-cbc-128
esp-aes aes aes
AES-CBC-192 Encryption Acceptable AES-GCM-256 IKEv1: aes 192
IKEv2: aes-cbc-192
esp-aes 192 aes-192 aes-192
AES-CBC-256 Encryption Acceptable AES-GCM-256 IKEv1: aes 256
IKEv2: aes-cbc-256
esp-aes 256 aes-256 aes-256
AES-GCM-128 Authenticated encryption NGE IKEv1: n/a
IKEv2: aes-gcm-128
esp-gcm 128 aes-gcm aes-gcm
AES-GCM-192 Authenticated encryption NGE aes-gcm-192 aes-gcm-192
AES-GCM-256 Authenticated encryption NGE IKEv1: n/a
IKEv2: aes-gcm-256
esp-gcm 256 aes-gcm-256 aes-gcm-256

6. under crypto isakmp policy (IKE) or crypto ike2 proposal (IKEv2)

7. in a crypto ipsec transform-set

8. under crypto ikev2 policy (IKEv2)

9. in a crypto ipsec ikev2 ipsec-proposal

Authentication/Integrity/Hash

Algorithm Operation Status Alternative QCR Mitigation IOS command10 IOS command11 IOS command12
DSA-768 Authentication Avoid DSA-3072
DSA-1024 Authentication Avoid DSA-3072
MD5 Integrity Avoid SHA-256
SHA-1 Integrity Legacy SHA-256
HMAC-MD5 Integrity Legacy HMAC-SHA-256 Short key lifetime IKEv1: hash md5
IKEv2: integrity md5
IKEv2: prf md5
esp-md5-hmac ah-md5-hmac
DSA-2048 Authentication Acceptable ECDSA-256
DSA-3072 Authentication Acceptable ECDSA-256
HMAC-SHA-1 Integrity Acceptable HMAC-SHA-256 IKEv1: hash sha
IKEv2: integrity sha1
IKEv2: prf sha1
esp-sha-hmac ah-sha-hmac
SHA-256 Integrity NGE SHA-384
SHA-384 Integrity NGE
SHA-512 Integrity NGE
HMAC-SHA-256 Integrity NGE IKEv1: hash sha256
IKEv2: integrity sha256
IKEv2: prf sha256
HMAC-SHA-384 Integrity ? ? IKEv1: hash sha384
IKEv2: integrity sha384
IKEv2: prf sha384
HMAC-SHA-512 Integrity ? ? IKEv1: n/a
IKEv2: integrity sha512
IKEv2: prf sha512
ECDSA-384 Authentication NGE
AES-GCM-128 Authenticated encryption NGE esp-gmac 128
AES-GCM-256 Authenticated encryption NGE esp-gmac 256

10. under crypto isakmp policy (IKE) or crypto ike2 proposal (IKEv2)

11. in a crypto ipsec transform-set for ESP

12. in a crypto ipsec transform-set for AH

SSH

SSH key exchange algorithms

Chart per draft-ietf-curdle-ssh-kex-sha2-09
curve25519-sha256 SHOULD
curve448-sha512 MAY
diffie-hellman-group-exchange-sha1 SHOULD NOT
diffie-hellman-group-exchange-sha256 MAY
diffie-hellman-group1-sha1 SHOULD NOT
diffie-hellman-group14-sha1 SHOULD
diffie-hellman-group14-sha256 MUST
diffie-hellman-group15-sha512 MAY
diffie-hellman-group16-sha512 SHOULD
diffie-hellman-group17-sha512 MAY
diffie-hellman-group18-sha512 MAY
ecdh-sha2-nistp256 SHOULD
ecdh-sha2-nistp384 SHOULD
gss-gex-sha1-* SHOULD NOT
gss-group1-sha1-* SHOULD NOT
gss-group14-sha1-* MAY
gss-group14-sha256-* SHOULD
gss-group15-sha512-* MAY
gss-group16-sha512-* SHOULD
gss-group17-sha512-* MAY
gss-group18-sha512-* MAY
gss-nistp256-sha256-* SHOULD
gss-nistp384-sha384-* SHOULD
gss-nistp521-sha512-* MAY
gss-curve25519-sha256-* SHOULD
gss-curve448-sha512-* MAY
rsa1024-sha1 MUST NOT
rsa2048-sha256 MAY

SSH encryption algorithms

chacha20-poly1305@openssh.com
aes128-ctr
aes192-ctr
aes256-ctr
aes128-gcm@openssh.com
aes256-gcm@openssh.com
aes128-cbc
aes192-cbc
aes256-cbc
3des-cbc

SSH MAC

hmac-sha1
hmac-sha1-96
hmac-sha2-256
hmac-sha2-512