.DMG files with passwords

Hello, i've created a .dmg file using Disk Utility to hide private stuff from anybody who decides to snoop around my mac. i put a 128-aes password i believe on it.

Is this hack proof is it easy to get into let me know so i don't make this mistake thinking people can't get into it.

Hack proof meaning is the encryption lever hack proof?

The 128 bit standard is sufficient, though 256 is becoming more of the standard.

Keep in mind the whole thing revolves around a password. So if you choose a dictionary password or or something with dictionary substitutions like f!$h you have a higher likely hood of being brute force challenged. Complex passwords are always best for protecting data.

Oh yeah,...don't save it in your keychain either,...

Even better... stay away from anything that may be incriminating or illegal, and if it's super sensitive such as bank details, or you work in legal or political circles, keep it on an external HD and keep it in a safe.