Which is the best "aes 128-cbc" or "aes 256 -gcm"

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Which is the best "aes 128-cbc" or "aes 256 -gcm"

L2 Linker

hi friends,

   I am trying to understand, which is the best among the below 2 IPSec encryptions?


1. "aes 128-cbc"
2. "aes 256 -gcm"

i am looking for opinions based on security and reliability. 


Thanks !!


Sourav Saha

Cyber Elite
Cyber Elite



We are using aes-256-cbc for encryption in our PA.


 From a cryptographic perspective, though, both AES-CBC and AES-GCM are highly secure.

GCM provides authentication, removing the need for an HMAC SHA hashing function. It is also slightly faster than CBC because it uses hardware acceleration (by threading to multiple processor cores).


AES-128 provides more than enough security margin for the foreseeable future. But if you're already using AES-256, there's no reason to change.”

A larger key size provides a higher safety margin against being cracked.


So i will prefer you to choose 256 instead of 128 bit key size if you want more security.


It all depends on the each company setup.

You can use any of those it is just matter of preference.




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Thanks for the suggestion. 


Sourav Saha
  • 2 replies
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