| Type | Purpose |
|---|---|
| Public | Store and share public data which can be seen by anyone. Using a public AtKey indicates it stores public and unencrypted plain text. |
| Self | Store data which can only be seen by the author of the AtKey. Using a self AtKey indicates it stores data intended for self, and contains encrypted data with keys only itself has. |
| Shared | Store and share private data which can only be seen by the owner and intended recipient. Using a shared AtKey indicates it points to data that is encrypted with someone else's key package. |
| Private | Store data which can only be seen by the owner, hidden by default. |
| Cached | Cache shared data from other atSigns for performance and offline mode. |
| Part | Meaning |
|---|---|
| sharedWith | This AtKey is shared with this Atsign, always starts with an @ symbol |
| key | Mandatory. This is the name you give it |
| namespace | The application namespace it's part of (e.g. my_app or contacts.favourites) |
| sharedBy | Mandatory. The owner/author of this AtKey |
| Type | Example | Meaning |
|---|---|---|
| Public AtKey | public:location@alice | A public AtKey with a record id of location shared by @alice (@alice authored this AtKey). This AtKey is prefixed with public: which means it holds public data that any Atsign can access, even without authentication. The AtValue that this key holds is expected to be plain text. |
| Private AtKey | privatekey:pk1@alice | A private AtKey with a record id of pk1 shared by @alice . No other Atsign can view this key except for @alice. |
| Shared AtKey | @bob:phone@alice | A shared AtKey with a record id of phone, shared with @bob, and shared by @alice. The AtValue is expected to be accessible by @bob's cryptographic keys. |
| Internal AtKey | _latestnotificationid.at_skeleton_app@alice | An internal AtKey with a record id of This does not show up in |
| Cached AtKey | cached:@bob:phone@alice | A cached AtKey with a record id of phone, shared with @bob and is shared with @alice. This is a key that would be expected to be cached in @bob's atServer, since bob here will be caching alice's data for faster retrieval. |
| Meta Attribute | Auto create? | Description |
| availableFrom | Yes | A Date and Time derived from the ttb (now + ttb). A Key should be only available after availableFrom. |
| ccd | No | Indicates if a cached key needs to be deleted when the Atsign owner who has originally shared it deletes it. |
| createdBy | Yes | Atsign that has created the key |
| createdOn | Yes | Date and time when the key was created. |
| expiresOn | Yes | A Date and Time derived from the ttl (now + ttl). A Key should be auto deleted once it expires. |
| isBinary | No | True if the value is a binary value. |
| isCached | No | True if the key is cached. |
| isEncrypted | No | True if the value is encrypted. |
| refreshAt | No | A Date and Time derived from the ttr. The time at which the key gets refreshed. |
| sharedWith | No | Atsign of the individual with whom the key has been shared. Can be null if not shared with anyone. |
| updatedOn | Yes | Date and time when the key was last updated. |
| ttb | No | Time to birth in milliseconds. |
| ttl | No | Time to live in milliseconds. |
| ttr | No | Time in milliseconds after which the cached key needs to be refreshed. A ttr of -1 indicates that the key can be cached forever. ttr of 0 indicates do not refresh. ttr of > 0 will refresh the key. ttr of null indicates the key is impossible to cache, hence, refreshing does not make sense (which has the same effect as a ttr of 0). |