This request affects the following components:

• iam
• embed
• identity
• infra for iam & embed

We need to make sure this is resilient to Mishti being down and we can use the current system for a period of time until Mishti is full ready and has had a successful epoch (90 day period).

Summary

• we will introduce the concept of epochs
• the VC structure will be changed:
  • we'll replace the hash attribute with nullifiers which will contain an array of 2 hashes:
    • the 1st will be the active hash of the epoch
    • the 2nd will be the future hash (the active hash in the next epoch)
• each epoch will use 2 private keys
  • active key.- will be used to sign VCs and onchain payloads and create the active hash
  • future key.- will be used to create the future hash. This key will become the active key in the next epoch.
• the functionality which issues the VCs in the new format should not be enabled by default, but should require a feature flag which is off by default
  • feature flags will be configured both in embed and iam services
• the configuration specific for this new feature should include the following env vars:
  • CURRENT_EPOCH_KEY
  • CURRENT_EPOCH_START_TIME - start time in iso format
  • NEXT_EPOCH_1_KEY
  • NEXT_EPOCH_1_START_TIME - start time in iso format
  • NEXT_EPOCH_2_KEY
  • NEXT_EPOCH_2_START_TIME - start time in iso format

Depends on:

• Embed: refactor identity package #3176

Acceptance criteria

GIVEN I am start / restart the iam or embed services
WHEN the service start
THEN they load the current and next epoch start date, end date and keys
AND I am able to claim the new credentials on the new /api/v0.0.0/verify endpoint

GIVEN the iam & embed services are running and we have 3 epoch configured (epoch 1 - current, epoch 2, epoch 3)
AND the end of the current epoch (and implicitly the start of the next epoch) is configured to be T
WHEN I make a request to /api/v0.0.0/verify before time T
THEN I get a VC signed with epoch 1 and hashes for epoch 1 and 2
AND WHEN I make a request to /api/v0.0.0/verify starting with time T
THEN I get a VC signed with epoch 2 and hashes for epoch 2 and 3