As always, it depends on the jurisdiction. The EU has the eIDAS [1] which allows simple signatures such as these for most form-free-contracts (the majority). There are however some, which need a digital cert and have to be encrypted.
And Switzerland ZertES: https://en.wikipedia.org/wiki/ZertES - There are not normally various levels of trust with afaik only QES (Qualified Electronic Signature), the highest level to legally be on the same level as a hand signature.
[1] https://en.wikipedia.org/wiki/EIDAS