Algorithm 1 Registering a device with the service registry.

Require:

B:   Global state of the blockchain.

P:   Service registry smart contract caller.

$C_{dev}$:   Device’s digital identity. Must be unique within an organization.

$I_{org}$: ID of the organization to which the device belongs.

$N_{dev}$:  Nickname of the device.

$D_{dev}$:   A short summary of the device’s function and usage.

$T_{dev}$: The date and time when the last update is made to the device information.

Ensure:

Device information is saved or updated in the blockchain.

1: if $WRITE\notin$ GetCallerPermissions $\left(P\right)$ then

2:  return error      ▹ Abort if caller is not allowed to update the blockchain

3: end if

4: $I_{dev}\leftarrow$ GenerateDeviceId $\left(C_{dev}\right)$  ▹ Generate device ID from its digital identity

5: if $I_{dev}\ne$ GetContractCallerId $\left(P\right)$ then

6:  return error           ▹ Abort if caller impersonates another device

7: end if

8: if $I_{org}\ne$ GetContractCallerOrgId $\left(P\right)$ then

9: return error        ▹ Abort if caller impersonates another organization

10: end if

11: $S_{dev}\leftarrow$ Serialize $(I_{dev},I_{org},N_{dev},D_{dev},T_{dev})$

12: $B[I_{org},I_{dev}]\leftarrow S_{dev}$

13: return $S_{dev}$