All perfect praise be to Allah
As of what i read, here are some points i got:
1- This is process is still one way, their is no successful attempt to get the freezed people back to life again.
2- At-least in america, you cannot legally freeze an alive human being, so you should be legally declared dead(which is mind being dead) before this process of freezing can begin.
So, by these 2 points what we can see is that this process is just IN A HOPE process, and their is no assurity of anything in this process. And also this costs a lot lot of money, for what? just for a hope that you might be able to delay your death time? While you are freezed and you are actually dead, just your body is preserved.
I would say this process is useless, at least for now, that we see no gain in freezing the bodies. While in islam we are ordered to bury the bodies as soon as possible after death. It is is not a good practice to keep bodies in freezers without a valid reason. Also true for true muslims Rasul Allah (sal Allahu alaihi wasallam) said:
“The world is a prison for a believer and Paradise for a non-believer.” [Muslim]
So, i would say this process seems against islam's basics. At least until it is proven that it works, by trying on some animals or some thing. If his proves to be successful on animals even, than we can talk about if we can do this process on humans or not. Until than it is not permissible.
NOTE: this is my opinion, i am not a mufti. I will try to ask some proper muftis about this interesting topic. These are my words based on my little knowledge and can be wrong. I will update my answer when i have some updates on this topic.
Allah knows best
If God wants cryonics to work it will. If he doesn't then it won't but God has granted us the brains to extend life in many ways. Think of heart transplants and CPR. If God didn't approve of life then we would have no medicine and we would be told to commit suicide but instead we have work to do here on earth and I believe even if cryonics wakes people up that eventually we will all die and face God. I do not try to second guess or tell God what is possible or not. Cryonics is simply pushing the limits of medicine. I think God approves of healing the sick and helping people to live longer. I think God supports cryonics as much as he supports CPR and other life saving practices.
Inshallah this is haraam. We as muslims know that once allah calls us back , this is it. To freeze your body to prolonge your life is like a form a shirk. You are basically saying even though allah specifically says he alone controls your time of birth and how long you live and exact time of death. Yet you try to use human technology and science to live longer that what was written, this is haraam astaghfirallah may allah forgive our way of thinking