Change:
16.3. <del> Handles are a third option to establish time-keeping next to nonces or timestamps.  Handles are opaque data intended to be available to all RATS roles that interact with each other, such as the Attester or Verifier, in specified intervals.  To enable this availability, handles are distributed centrally by the Handle Distributor role over the network.  As any other role, the Handle Distributor role can be taken on by a dedicated entity or collapsed with other roles, such as a Verifier.  The use of handles can compensate for a lack of clocks or other sources of time on entities taking on RATS roles.  The only entity that requires access to a source of time is the entity taking on the role of Handle Distributor. Handles are different from nonces as they can be used more than once and can be used by more than one entity at the same time.  Handles are different from timestamps as they do not have to convey information about a point in time, but their reception creates that information.  The reception of a handle is similar to the event that increments a relative tickcounter.  Receipt of a new handle invalidates a previously received handle. In this example, Evidence generation based on received handles always uses the current (most recent) handle.  As handles are distributed over the network, all involved entities receive a fresh handle at roughly the same time.  Due to distribution over the network, there is some jitter with respect to the time the Handle is received, time(HR), for each involved entity.  To compensate for this jitter, there is a small period of overlap (a specified offset) in which both a current handle and corresponding former handle are valid in Evidence appraisal: "validity-duration = time(HR'_v) + offset - time(HR_v)".  The offset is typically based on a network's round trip time.  Analogously, the generation of valid Evidence is only possible, if the age of the handle used is lower than the validity- duration: "time(HR_v) - time(EG_a) < validity-duration". </del> <ins> The following example illustrates a hypothetical Passport Model solution that uses handles instead of nonces or timestamps.  In this example, Evidence generation based on received handles always uses the current (most recent) handle.  As handles are distributed over the network, all involved entities receive a fresh handle at roughly the same time.  Due to distribution over the network, there is some jitter with respect to the time the Handle is received, time(HR), for each involved entity.  To compensate for this jitter, there is a small period of overlap (a specified offset) in which both a current handle and corresponding former handle are valid in Evidence appraisal: "validity-duration = time(HR'_v) + offset - time(HR_v)". The offset is typically based on a network's round trip time. Analogously, the generation of valid Evidence is only possible, if the age of the handle used is lower than the validity-duration: "time(HR_v) - time(EG_a) < validity-duration". </ins> From the point of view of a Verifier, the generation of valid Evidence is only possible, if the age of the handle used in the

Discussion:
Per last week's design team discussion. Signed-off-by: Dave Thaler
In general, I like the re-introduction of the "timekeeping" subsections a lot. +1