ok, I used to be a boxer and there are many things you can do to increase punching power and speed:
1: INCREASE YOUR FOOT SPEED; your feet and the speed at which you strike effects how effective your punch is. Take a jump rope and start doing about 200 a day. Then take duct tape and make a cross on the ground. From there, you can invent a variety of agility excercises.
2: DO BARE KNUCKLE PUSHUPS ; Find a hard surface such as concrete, hardwood floor, or tile. Then do normal pushups but instead of using your palms and fingers, use your knuckles. You would not believe how much this increases your knuckle strength.
3. INCREASE POWER, NOT JUST STRENGTH ; power is a measure of speed and strength in lifting. You need to be incredibly explosive when you lift weights and perform your cardio
4. RUN, RUN, and RUN SOME MORE : The number one thing that affects how well you throw a punch is your endurance... if you have crappy endurance, your form will be off and you will tire, and your punches will no longer pack any power
5. PERFECT FORM: If you have great form, you have an excellent punch. Learn the position that you feel is right for your knuckles in the ideal punch. Knuckle placement, stance, and strike pattern will make your punches more effective.
Bare knuckle fighting is risky, just remember, don't throw the first punch, land the first deadly one.