STRIDE property	Requirement	Remark
Authentication	Not a risk. Registration is publicly accessible
Integrity	The homeserver must perform checks to ensure the user id entered is valid as per specification
Non-repudiation	The user or its client must prove possession of authentication key material
Confidentiality	No requirements besides the general confidentiality requirements
Availability	User registration MAY be restricted when the homeserver has limited resources
Authorization	Not a risk. No authorization required for registration
Spam prevention	To mitigate spam attacks downstream of user registration, the homeserver MAY restrict user registration

STRIDE property	Requirement	Remark
Authentication	AS credentials are publicly available to everyone
	Clients must be able to authenticate intermediate AS credentials using the corresponding AS credential
	The basic confidentiality and authentication requirements must hold
Integrity	Not a risk as this is a read-only operation
Non-repudiation	Not a risk. There is no need to trace
Confidentiality	Basic confidentiality and authentication requirements must hold
	Enqueued messages must be encrypted according to the specification
Availability	Clients must always be able to obtain AS credentials
Authorization	Not a risk. All clients are allowed to obtain AS credentials
Spam prevention	Not a risk as getting AS credentials is not message-sending