NSA Litoměřice crawled github for 1.5 million public ssh keys. The crawling was performed in the beginning of August 2015. You can download:

• List of usernames registered on GitHub (73 MB)
• List of public keys (420 MB)

Intended use of the dataset is decloaking remote users based on SSH key fingerprint and factoring weak keys with Batch-GCD. However, we decided to publish the dataset, so you can be creative!