What issue? Please cite your sources... The best part of Bitcoin is that when a problem is found, people can upgrade the software and move past it. Even if the

What issue? Please cite your sources... The best part of Bitcoin is that when a problem is found, people can upgrade the software and move past it. Even if there was a weakness in certain cipher, the way Bitcoin is constructed it would take multiple serious vulnerabilities in ECDSA, RIPEMD160 and SHA256 _at the same time_ to have any effect on the security for the end user. Bitcoin itself has been around for 4 years with some serious attackers already on the core protocol, and it is still pretty much unchanged. It is unfortunately much more rewarding and much easier (sadly, but that is improving) attacking services that use Bitcoin.