# `BoundedAuthorityProtocol.V1.KeyTransition`
[🔗](https://github.com/baselabs/bounded_authority_protocol/blob/v1.0.0/lib/bounded_authority_protocol/v1/key_transition.ex#L1)

Closed deterministic historical-key transition signing input.

## Fields

* `transition_id` - the transition identity: non-empty StringOrURI of at most `identifier_bytes`
  (512) UTF-8 bytes.
* `chain_id` - the chain identity: non-empty StringOrURI of at most `identifier_bytes` (512) UTF-8
  bytes.
* `effective_at` - when the next key takes over, integer Unix time in seconds; it must lie inside
  both keys' validity windows.
* `current_key_id` - the identifier of the signing (current) key: 1 to `kid_bytes` (128) bytes of
  ASCII letters, digits, `-`, `.`, `_` or `~`.
* `current_public_key` - the current key's raw public key in the suite's fixed width: 32-byte
  Ed25519 under contract-majors 1 and 2, the 65-byte uncompressed SEC1 P-256 point `0x04 || x ||
  y` under contract-major 3; it signs the transition.
* `next_key_id` - the identifier of the next key: 1 to `kid_bytes` (128) bytes of ASCII letters,
  digits, `-`, `.`, `_` or `~`; it may equal `current_key_id`.
* `next_public_key` - the next key, in the same width; it must differ from `current_public_key`.

# `t`

```elixir
@type t() :: %BoundedAuthorityProtocol.V1.KeyTransition{
  chain_id: binary(),
  current_key_id: binary(),
  current_public_key: binary(),
  effective_at: integer(),
  next_key_id: binary(),
  next_public_key: binary(),
  transition_id: binary()
}
```

Producer input for one historical-key transition.

---

*Consult [api-reference.md](api-reference.md) for complete listing*