Rc7 Cracked [verified] -

Cryptanalysis of RC7 (PDF)

The authors conclude that RC7 is not as secure as previously thought and that a large number of rounds can be distinguished from a random permutation. They also show that a practical attack on RC7 is feasible, which can recover the secret key. rc7 cracked

You're referring to the alleged cracking of the RC7 block cipher! Cryptanalysis of RC7 (PDF) The authors conclude that

Here is the full paper: