=Usability of WKD

==Criteria for implementing WKD with a good usability
In a [[https://wiki.gnupg.org/WKD/BachelorThesisIncreaseWKDUsage2021|bachelor thesis]] two use cases were developed which describe how users who don't have much experience with encryption can encrypt emails or check signatures with little effort and a good usability.
\\These use cases are used to name criteria which help developers to improve the usability of their products. They are also useful when it comes to a comparison between the usability of different products.
\\WKD-keys have a basic trust because they are fetched from WKD-servers that belong to email-providers. Reasons for that are that email-provider know that a pubkey belongs to an email-address and that email-providers usually have a higher security level than private persons who maintain a server. Some criteria reflect this basic trust of WKD-keys.

*C1: The product supports the direct method of WKD
*C2: The product supports the advanced method of WKD
*C3: The product is ready for WKD without any preparations after a clean installation
*C4: WKD is offered in the area where users enter an email-address. To fulfill this criterion it's sufficient that there is a button to start a key lookup. It's not necessary that WKD will be executed automatically. But, users shouldn't have to open more than one additional window.
*C5: WKD is offered in the area where users check the signature of an email. Like for K3 users shouldn't have to open more than one additional window.
*C6: The product uses WKD automatically when users enter an email-address in the area where they can compose an email. The users do not have to press a button to retrieve a key via WKD.
*C7: When the product has access to keys which were directly imported and don't contain any information about their trust and a WKD-key it should automatically use the WKD-key (in the area to **compose** an email).
*C8: When the product has access to keys which were directly imported and don't contain any information about their trust and a WKD-key it should automatically use the WKD-key (in the area to **check the signature** of an email).
*C9: The product distinguishes between keys without any information about their trust and keys that have at least a basic trust (e.g. WKD-keys or marginal valid keys in the web of trust) and displays this difference in the area to **compose** an email. In this criterion it doesn't matter, how the trust is calculated.
*C10: The product distinguishes between keys without any information about their trust and keys that have at least a basic trust (e.g. WKD-keys or marginal valid keys in the web of trust) and displays this difference in the area to **check the signature** of an email. In this criterion it doesn't matter, how the trust is calculated.
*C11: Displays that WKD-keys have a basic trust (**compose**).
*C12: Displays that WKD-keys have a basic trust (**check of signature**).
*C13: Displays different levels of trust (**compose**).
*C14: Displays different levels of trust (**check of signature**).

==Usability of different products

===Balsa

Tested version: 2.6.3

|=Criterion|=Fullfilled|
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes|
|=C3: WKD-ready|{{icon-error.png}} no|
|=C4: Offered in compose area|{{icon-error.png}} no|
|=C5: Offered in signature area|{{icon-error.png}} no|
|=C6: Automatic WKD (Compose)|{{icon-error.png}} no|
|=C7: Prefer WKD-keys (Compose)|
|=C8: Prefer WKD-keys (Signature)|
|=C9: Can display basic trust (Compose)|{{icon-error.png}} no|
|=C10: Can display basic trust (Signature)|{{checkmark.png}} yes|
|=C11: Displays basic trust for WKD-keys(Compose)|
|=C12: Displays basic trust for WKD-keys (Signature)|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|{{icon-error.png}} no|

===Claws Mail

Tested version: 3.18.0/4.0.0

|=Criterion|=Fullfilled
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes|
|=C3: WKD-ready|{{icon-error.png}} no|
|=C4: Offered in compose area|{{icon-error.png}} no|
|=C5: Offered in signature area|{{checkmark.png}} yes|
|=C6: Automatic WKD (Compose)|{{icon-error.png}} no|
|=C7: Prefer WKD-keys (Compose)|{{icon-error.png}} no|
|=C8: Prefer WKD-keys (Signature)|{{icon-error.png}} no|
|=C9: Can display basic trust (Compose)|{{icon-error.png}} no|
|=C10: Can display basic trust (Signature)|{{checkmark.png}} yes|
|=C11: Displays basic trust for WKD-keys(Compose)|{{icon-error.png}} no|
|=C12: Displays basic trust for WKD-keys (Signature)|{{icon-error.png}} no|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|{{checkmark.png}} yes|

===FairEmail

Tested version: 1.1776

|=Criterion|=Fullfilled
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes|
|=C3: WKD-ready|{{icon-error.png}} no|
|=C4: Offered in compose area|{{icon-error.png}} no|
|=C5: Offered in signature area|{{icon-error.png}} no|
|=C6: Automatic WKD (Compose)|{{icon-error.png}} no|
|=C7: Prefer WKD-keys (Compose)|{{icon-error.png}} no|
|=C8: Prefer WKD-keys (Signature)|{{icon-error.png}} no|
|=C9: Can display basic trust (Compose)|{{icon-error.png}} no|
|=C10: Can display basic trust (Signature)|{{icon-error.png}} no|
|=C11: Displays basic trust for WKD-keys(Compose)|{{icon-error.png}} no|
|=C12: Displays basic trust for WKD-keys (Signature)|{{icon-error.png}} no|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|{{icon-error.png}} no|

===K9Mail

Tested version: 5.806

|=Criterion|=Fullfilled
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes|
|=C3: WKD-ready|{{icon-error.png}} no|
|=C4: Offered in compose area|{{icon-error.png}} no|
|=C5: Offered in signature area|{{icon-error.png}} no|
|=C6: Automatic WKD (Compose)|{{icon-error.png}} no|
|=C7: Prefer WKD-keys (Compose)|{{checkmark.png}} yes|
|=C8: Prefer WKD-keys (Signature)|{{icon-error.png}} no|
|=C9: Can display basic trust (Compose)|{{checkmark.png}} yes|
|=C10: Can display basic trust (Signature)|{{checkmark.png}} yes|
|=C11: Displays basic trust for WKD-keys(Compose)|{{icon-error.png}} no|
|=C12: Displays basic trust for WKD-keys (Signature)|{{icon-error.png}} no|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|{{icon-error.png}} no|

===KMail

Tested version: 5.18.3

|=Criterion|=Fullfilled
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes|
|=C3: WKD-ready|{{icon-error.png}} no|
|=C4: Offered in compose area|{{checkmark.png}} yes|
|=C5: Offered in signature area|{{icon-error.png}} no|
|=C6: Automatic WKD (Compose)|{{checkmark.png}} yes|
|=C7: Prefer WKD-keys (Compose)|{{icon-error.png}} no|
|=C8: Prefer WKD-keys (Signature)|{{icon-error.png}} no|
|=C9: Can display basic trust (Compose)|{{checkmark.png}} yes|
|=C10: Can display basic trust (Signature)|{{checkmark.png}} yes|
|=C11: Displays basic trust for WKD-keys(Compose)|{{icon-error.png}} no|
|=C12: Displays basic trust for WKD-keys (Signature)|{{icon-error.png}} no|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|{{icon-error.png}} no|


===Mailvelope

Tested version: 4.4.1

|=Criterion|=Fullfilled|=Comment
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes|Was added in 4.5.0
|=C3: WKD-ready|{{checkmark.png}} yes|
|=C4: Offered in compose area|{{checkmark.png}} yes|
|=C5: Offered in signature area|{{icon-error.png}} no|
|=C6: Automatic WKD (Compose)|{{checkmark.png}} yes|
|=C7: Prefer WKD-keys (Compose)|{{icon-error.png}} no|
|=C8: Prefer WKD-keys (Signature)|
|=C9: Can display basic trust (Compose)|{{icon-error.png}} no|
|=C10: Can display basic trust (Signature)|
|=C11: Displays basic trust for WKD-keys(Compose)|{{icon-error.png}} no|
|=C12: Displays basic trust for WKD-keys (Signature)|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|

===GpgOL (Outlook)

Tested version: 2.5.1

|=Criterion|=Fullfilled|
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes|
|=C3: WKD-ready|
|=C4: Offered in compose area|{{checkmark.png}} yes|
|=C5: Offered in signature area|{{icon-error.png}} no|
|=C6: Automatic WKD (Compose)|{{checkmark.png}} yes|
|=C7: Prefer WKD-keys (Compose)|
|=C8: Prefer WKD-keys (Signature)|
|=C9: Can display basic trust (Compose)|{{icon-error.png}} no|
|=C10: Can display basic trust (Signature)|{{checkmark.png}} yes|
|=C11: Displays basic trust for WKD-keys(Compose)|{{icon-error.png}} no|
|=C12: Displays basic trust for WKD-keys (Signature)|{{checkmark.png}} yes|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|{{checkmark.png}} yes|

===Thunderbird

Tested version: 97.0a1

|=Criterion|=Fullfilled|
|=C1: Direct method|{{checkmark.png}} yes|
|=C2: Advanced method|{{checkmark.png}} yes
|=C3: WKD-ready|{{icon-error.png}} no|
|=C4: Offered in compose area|{{icon-error.png}} no|
|=C5: Offered in signature area|{{icon-error.png}} no|
|=C6: Automatic WKD (Compose)|{{icon-error.png}} no|
|=C7: Prefer WKD-keys (Compose)|{{icon-error.png}} no|
|=C8: Prefer WKD-keys (Signature)|{{icon-error.png}} no|
|=C9: Can display basic trust (Compose)|{{icon-error.png}} no|
|=C10: Can display basic trust (Signature)|{{icon-error.png}} no|
|=C11: Displays basic trust for WKD-keys(Compose)|{{icon-error.png}} no|
|=C12: Displays basic trust for WKD-keys (Signature)|{{icon-error.png}} no|
|=C13: Displays different levels of trust (Compose)|{{icon-error.png}} no|
|=C14: Displays different levels of trust (Signature)|{{icon-error.png}} no|