It would make it a lot easier for LinkedIn to identify whose hashes were leaked because with a salt, all passwords would be unique. It would also make rainbow tables useless.
But in this day and age, the bigger problem is how fast you can compute the hashes, salt or no. With GPUs you can calculate a few hundred million(depending on the hashing algorithm) per second, making the algorithm used the real vulnerability.
Best practice involves increasing the calculation time of you're algorithm. Theoretically, you could just rehash y few thousand times in a loop, throwing in a salt here and there, but practically, you should just use bcrypt or scrypt.
But in this day and age, the bigger problem is how fast you can compute the hashes, salt or no. With GPUs you can calculate a few hundred million(depending on the hashing algorithm) per second, making the algorithm used the real vulnerability.
Best practice involves increasing the calculation time of you're algorithm. Theoretically, you could just rehash y few thousand times in a loop, throwing in a salt here and there, but practically, you should just use bcrypt or scrypt.