Wikipedia - SHA-2 says
SHA-224 is identical to SHA-256, except that:
- the initial variable values h0 through h7 are different, and
- the output is constructed by omitting h7.
The use of a different initial value ensures that a truncated SHA-256 message digest value cannot be mistaken for a SHA-224 message digest value computed on the same data.
Is the above quoted reason the only reason why SHA-224 and SHA-256 use different initial values?
Why is it important to make sure that a SHA-256 message digest value cannot be mistaken for a SHA-224 message digest value?
If we use the same initial values for both hash functions, will the security of either hash function worsen? If yes, how?