20 Matching Annotations
  1. Jun 2024
    1. This enables an extremely beneficial property of TELs; that is, the verifiability of transaction events in the TEL persists in spite of changes to Key States in the sealing KEL. In other words, the verifiability of transaction events persists in spite of changes in the Key State
  2. May 2024
    1. Using seals, the delega-tor’s and delegate’s event streams are cross linked together
    2. A nested set of delegation levels may be used to form a dele-gation chain or a delegation tree
    3. In some critical interactions, however, the trade-off between convenience and security madeby reusing signing keys for multiple interaction events may not be acceptable. In this case, amore secure approach is to combine an interaction event with a rotation event by adding a pay-load data structure to the rotation event.
    4. To elaborate, a successful live exploit must compromise the unexposed next set of private keysfrom the public-keys declared in the latest rotation
    5. Figure 11.5. KERL for a Recovery Rotation Event.

      Rotation event as authorization of below events.

    6. The controller is responsible to promulgate a mutually consistent set of receipts, i.e. a suffi-cient agreement of size M ≥ M C .

      Why? Witnesses can gossip with each other acks about events they learned from the controller.

      As mentioned further.

    7. Without a threshold a validator may choose to hold a controller ac-countable upon any evidence of duplicity which may make the service fragile in the presence ofany degree of such faulty behavior
    8. Suppose instead that N = 3F + 1 , then a correctagreement is guaranteed as before but the agreement will have 2F + 1 nodes (quorum size) anddespite some F of those 2F + 1nodes becoming unresponsive, the remaining F + 1 honest andresponsive nodes will be able to propagate that correct safe agreement to the next round

      The reason behind N=3F+1, is that F nodes may behave duplicitly. So we need ((N-F) / 2) + 1 to have it safe.

    9. But there is no guarantee that the nodes in agreement (quorum) will knowthey came to agreement in a subsequent round because as many as F of the nodes in agreementin a given round may subsequently become unresponsive in the next round

      But we have f+1 for agreemend, so it will be live.

    10. This may be called a multi-controller or collec-
    11. An escrow cache of unverified out-of-order event provides an opportunity for malicious at-tackers to send forged event that may fill up the cache as a type of denial of service attack. Forthis reason escrow caches are typically FIFO (first-in-first-out) where older events are flushed tomake room for newer events.

      This may misfire, when there's a ton of valid events to sync, whose amount is greater than the cache limit.

      May happen when adding a new witness, requiring to sync the entire history. (do we need to provide it the entire history though? only the last not-yet-verified events are of interest for the controller to be signed by the witness)

    12. Event escrow isan optional implementation specific configurable capability of controllers and witnesses imple-mentations
    13. Each time the controller connects to awitness to send new events and collect the new event receipts, it also sends the receipts it has re-ceived so far from other witnesses
    14. When network bandwidth is less constrained then a gossip proto-col might provide full dissemination with lower latency than a round robin protocol
    15. When a rotation amends the witnesses it includes the new tally, the setof pruned (removed) witnesses and the set of newly grafted (added) witnesses. This is shownbelow.