Enable highly secure channels

[dominic22]

The current authentication is based on JWT with a lifespan of 24h.

To enable more trusted data a channel shall be optionally defined as high secure channel or top secret channel. (to be named)

In this case the data must be signed when writing to the channel. For instance data must be hashed and signed. The signed hash then can be validated by the api and only if it is valid it will be written to the channel.