Physical oracle services?

[tomsanta222]

IS there somewhere a physical oracle service for verifying the authenticity of a signature in a transaction? like a physical key...

[HeRetiK]

What do you mean by "physical key", what are you trying to achieve? If you are looking for a hardware device to verify signed messages look into hardware wallets such as Trezor or Ledger:

https://trezor.io/

https://www.ledgerwallet.com/products/ledger-nano-s