ok i studied aikido from age 11 to 15 and I am thinking about coming back after a little break since school is calming down again.

My sensei taught us all kinds of techniques, and we practiced techniques beyond our ranks since we had gotten our basics down well and they could be used for the higher level techniques. I also saw demonstrations from my sensei and his sensei and they all seemed to use just variations of what we learned or more advanced techniques based off the basics of aikido.

I was just wondering if there are any more dangerous and complicated techniques that blackbelts only practice or teach in the presence of other high ranks that I would get to learn if I got higher in rank??

Sure jujigarami koshinage comes to mind

well its not so secret if you post it now is it but anways i think ive been taught that technique it sounds familiar

Everything is secret until you learn it. And you only get to be a high grade when you are good at the techniques - therefore - the biggest secret is to be good at the techniques.

.............Its a secret

This from the horse's mouth:
"Progress comes to those who train and train; Reliance on secret techniques will get you nowhere".

- The Art of Peace (tr. John Stevens)

Having said that, the real secret of aikido is in the ukemi. Once you master the ukemi, you will have no problem mastering any technique.

There are no secrets. Everything is basic. Everything is simple - when you know how. Just keep practising.

You don't even need techniques, or to think of them at least, when you achieve the right state of mind. Same in Taiji.

Advanced moves are nothing more than basics that are used in combinations, or under different scenarios than what they were originally taught for.

Understand your basics, and you will understand the advanced moves.

They are secret...I can not tell you....

Putting this in perspective of my sensi whom does my JKD and Kali, what good are 27 different stick patterens and strikes if you can only apply 2 of them? If you can get your basic's down better then the other guy, then you stand a better chance against him, even if he knows more. Basic is usually simple, so it is more effecient. Why throw a jab cross hook when you train your jab to have the force of all three?

"Sure jujigarami koshinage comes to mind"
Very definitely, a very hard technique from which to escape and still have
one's neck in one piece.

"Everything is secret until you learn it. And you only get to be a high grade when you are good at the techniques - therefore - the biggest secret is to be good at the techniques."

I just found this forum, havent looked at it for awhile but I am enjoying your discourse.
I study with Mitsugi Saotome's dojo in Florida, from time to time, and they have excellent Aikido there.
When the higher ranking and more experienced guys engage in randori, I am totally unable to repeat the technique in succession. But I am able to recognize how many kihon are connected to make a more involved and complicated waza. After over 20 years I still feel like an Aiki-Baby.

Advanced/secret techniques are merely the basics done better...

I'm certainly no expert on the subject as I've only trained for about 3 years. However, my experience suggests that there aren't any secret techniques. There are however techniques that are less frequently taught or not taught in specific dojos. For example, I trained at a dojo near my parents house during this previous christmas. The head instructor was away so each student would pick a move to demonstrate and every one would practice that move. I chose tsuki rokyo. None of the students in that particular dojo seemed familiar with rokyo so it may have seen like an advanced or secret technique. I also know some schools often don't teach gokyo. I've also seen a couple of moves that I was unfamiliar with but I certainly don't think they are secret techniques.