As you are reading this blog, I guess you are interested in security and cryptography. Also, you are open minded person. Do you like challenges that can help you to earn money? If you like it, this is good place to visit – RSA laboratories: https://www.rsasecurity.com/rsalabs/node.asp?id=2091. RSA is currently holding three cryptographic challenges.
Also visit https://mathworld.wolfram.com/news/2005-05-10/rsa-200/ to see how RSA-200 was factored by German Federal Agency for Information Technology Security (BSI).
Have a fun.