Actually i have two websites and the one which is suppose to receive the data is not parametered in https and will not be. Can I use the JWT technique to send form data from one server two another on a http connnection. I'm thinking of big textarea messages. The first website receives the data with https connection stores it in a JWT and sends it with curl to the second server with http connection. I know that it's not the original purpose of JWT but do you think good partice? Do i risk to encounter errors during encoding and decoding en large amounts of text?
I suggest you use rsync. It can work over a SSH connection to protect your data and is smart enough to sync only changed files.
JWT are not designed to send large amount of data between servers. It is in fact a format to transmit claims between servers or between a client and a server. Those claims can be digitally signed (JWS - See RFC7515), encrypted (JWE - See RFC7516) or both (signed then encrypted). They are usually compact as they are mainly used in a web context.