The problem isn't the number of bits (yet). The problem is the choice of hash. A truncated sha2 would still be fine for years to come (barring a sha2 break, w

The problem isn't the number of bits (yet). The problem is the choice of hash. A truncated sha2 would still be fine for years to come (barring a sha2 break, which doesn't look imminent). 160bits may not be a huge margin, but it's still enough.