AWS CloudFormation
User Guide (API Version 2010-05-15)

Creating an EC2 Key Pair

The use of some AWS CloudFormation resources and templates will require you to specify an Amazon EC2 key pair for authentication, such as when you are configuring SSH access to your instances.

Amazon EC2 key pairs can be created with the AWS Management Console. For more information, see Amazon EC2 Key Pairs in the Amazon EC2 User Guide for Linux Instances.