question about winrar passwords

2Hero:
The main performance fall not in AES encrypting itself but in generating encryption key. The last one takes long time when using WinRAR.
You can speed up WinRAR breaking by brute-forcing decryption key, not password. But it'll make no sense due to a very big number of possible keys

[Hero]

hi amitophia
I'm not a professional in encryption algorithms,but I know that AES is an symmetric
algothirm,that means the encryption and decryption keys are the same.
What do you mean by:

You can speed up WinRAR breaking by brute-forcing decryption key, not password.

You mean that password is deferent by the AES encryption/decryption keys?
(I always think that they should get the AES 128bits key by making a simple
padding from your password.)

sincerely yours