1. Not necessarily. Salts have to turn a string no matter how small into a string (well, base-16 number in md5's and sha1's case) of a given size. The fewer characters the string is the more values overlap, but the larger the string is the more patterns it reveals that can allow it to be reverse-engineered.Keep in mind that these hashing functions are all advanced mathematical algorithms.

2. In a closed source app, there is no best way. Just attach something anywhere on the string and it will throw the entire hash out of whack.

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