# Life and Rift

Associated to every Azimuth point are two non-negative integers known as *life* and *rift*. This numbering system partition messages according to the quantity of networking key changes and quantity of [breaches](https://docs.urbit.org/user-manual/id/guide-to-resets), respectively. This is explained in more detail below. These values are utilized by [Ames](https://docs.urbit.org/urbit-os/kernel/ames) and [Jael](https://docs.urbit.org/urbit-os/kernel/jael) to ensure that communication between ships is always done with the most recent set of networking keys, and that networking state is appropriately reset when a breach has occurred.

Every ship begins with a `$life` and `$rift` of 0. For galaxies, stars, and planets, these values are stored in the [Azimuth PKI](https://docs.urbit.org/azimuth-eth#points) as `keyRevisionNumber` and `continuityNumber`, while for moons, these values are stored by their parent. Comets cannot change their networking keys, nor can they breach, and so their `$life` and `$rift` are always 0.

You can check your current `$life` and `$rift` number by running the `+keys our` generator in dojo. You can inspect another ship's `$life` and `$rift` by running `+keys ~sampel-palnet`.

## Life <a href="#life" id="life"></a>

A ship's `$life`, or *key revision number*, is a count of the number of times which a ship's networking keys have been altered. The initial value of each key is always zero, and the initial `$life` is always 0.

Thus, setting the keys of a ship to a nonzero value for the first time will increment the `$life` from 0 to 1. Rotating to a new set of keys will then increment the `$life` to 2. Setting the keys back to zero would increment the `$life` once more, to 3.

## Rift <a href="#rift" id="rift"></a>

A ship's `$rift`, or *continuity number*, is a count of the number of times that a ship has breached, also known as broken continuity.

In other words, a ship's `$rift` will remain at 0 until the first time it is breached.

Network-wide breaches do not affect the `$rift` of any ship. They are only used to count the number of personal breaches.

## Edge cases <a href="#edge-cases" id="edge-cases"></a>

Configuring the keys to the same value they already were (i.e. a no-op) is possible, but has no effect on the `$life`. Thus `$life` is actually a measure of networking key *revisions*, and not the number of times they've been set.

Thus under ordinary circumstances, a breach will increment both `$life` and `$rift` since a breach typically also involves changing the networking keys. However, it is possible to breach without changing the networking keys. If the new keys specified as part of a breach are the same as the old, `$rift` will increment while `$life` will not.