For a long time I have been troubled by the question of whether I can open a door without having a card for it and if possible, if someone can explain to me how I will be satisfied 
.
1 Like
In almost all cases it is impossible. Though, if you pull hard enough, any dor will open eventually, so you probably need to be more specific.
4 Likes
Not to mention that most likely it wouldn’t be legal to open the door if you don’t have a card for it …
1 Like
Yes, I can open lot’s of doors without a key or a card but I only do so with permission. I did this very thing for my parent last summer when they locked their door and forgot their keys. I know lots of people paid to do so regularly.
Try the most frequent combinations and hope to hit a master key or a bug or try all possible combinations and wait forever to get the correct code assuming simple tech like 125 khz with limited possibility…
Do you mean copying their key before? Or some exploits?
Lock picking. I research electronic and physical security.