Specify how cacheSignature is encoded

Author: bitfl0wer

docs/Protocol Specifications/core.md

@@ -1619,12 +1619,12 @@ This kind of attack mentioned above has been considered and mitigated in polypro
 is achieved through API behaviors enabling the fetching of actor ID-Certs with additional information
 attached to the response body. The additional information is structured as follows:
 
-| Field name            | JSON type | Actual type (if different from JSON type) | Description                                                                                                                                                                           |
-| --------------------- | --------- | ----------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| `cacheValidNotBefore` | String    | Unsigned 64-bit integer                   | UNIX timestamp that specifies the time from which this cache entry may be treated as valid.                                                                                           |
-| `cacheValidNotAfter`  | String    | Unsigned 64-bit integer                   | UNIX timestamp that specifies a time until which this cache entry may be treated as valid.                                                                                            |
-| `cacheSignature`      | String    | -                                         | Signature generated by the home server. This signature can be verified using the home servers' public identity key.                                                                   |
-| `invalidatedAt`       | String?   | Unsigned 64-bit integer                   | If present, represents a UNIX timestamp at which the certificate was [invalidated](#614-early-revocation-of-id-certs) on. Certificate was not prematurely invalidated if not present. |
+| Field name            | JSON type | Actual type (if different from JSON type) | Description                                                                                                                                                                                                         |
+| --------------------- | --------- | ----------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `cacheValidNotBefore` | String    | Unsigned 64-bit integer                   | UNIX timestamp that specifies the time from which this cache entry may be treated as valid.                                                                                                                         |
+| `cacheValidNotAfter`  | String    | Unsigned 64-bit integer                   | UNIX timestamp that specifies a time until which this cache entry may be treated as valid.                                                                                                                          |
+| `cacheSignature`      | String    | -                                         | Signature generated by the home server. This signature can be verified using the home servers' public identity key. Signature bytes, encoded in [Hexadecimal](https://en.wikipedia.org/wiki/Hexadecimal) (base-16). |
+| `invalidatedAt`       | String?   | Unsigned 64-bit integer                   | If present, represents a UNIX timestamp at which the certificate was [invalidated](#614-early-revocation-of-id-certs) on. Certificate was not prematurely invalidated if not present.                               |
 
 A server generates the `cacheSignature` by concatenating the serial number of the ID-Cert in
 question with the `cacheValidNotBefore` timestamp, the `cacheValidNotAfter` timestamp, and the `invalidatedAt`