Possibility of conflict between access keys ?

[Pierre]

Is it possible that an access keys added to a repository R in a project A can conflict with same access keys added to a project B.

Because what I experienced looked like it, I was never able to clone a repository S from project B, the server kept returning Unauthorized, until I added that access key to S, then I cloned S successfully

[Ben]

Hey Pierre,

Repository Access keys can be used across multiple repositories to provide read-only access, these can consist of the same public SSH key per-repository or can be different depending on individual need. For your purposes I would recommend sharing access keys between projects to ensure that access is granted between projects.

The only time a conflict should occur is if there is already an existing account-level SSH key configured in Personal Settings > SSH Keys - this cannot be used as a repository access key as it can't also be associated with an account:
https://support.atlassian.com/bitbucket-cloud/docs/add-access-keys/ 

Hope this helps.

Cheers!

- Ben (Bitbucket Cloud Support)