Cryptographic hash algorithms such as ``++MD2++``, ``++MD4++``, ``++MD5++``, ``++MD6++``, ``++HAVAL-128++``, ``++HMAC-MD5++``, ``++DSA++`` (which uses ``++SHA-1++``), ``++RIPEMD++``, ``++RIPEMD-128++``, ``++RIPEMD-160++``, ``++HMACRIPEMD160++`` and ``++SHA-1++`` are no longer considered secure, because it is possible to have ``++collisions++`` (little computational effort is enough to find two or more different inputs that produce the same hash).
