The lost challenges from IRISSCON 2012 are now available and added to the wechall rankings.
The CTF/convention has taken place in November 2012, and these challenges were not included due to the high amount of challenges there.
The author, Damien has made 7 of the lost exploits, cracking and forensic challenges available on his website, and you are welcome to try them out.
According to him, further challenges could be released there, but not in high quantities, as he is busy working as a software engineer.
Of course interest in security is a must in this field .