Lost Key for encrypted forms

I accidentally deleted the key to access some encrypted forms. Is there a way I can obtain this? 

The only way to decrypt your form is with the private key. If you deleted it please check your trash can? Because we don't store copies of keys on our servers. 

Note that you can disable encryption. This will only affect new submissions on your form. The old submissions will remain encrypted.

Encrypted Forms and How to Use Them