In many cryptocurrency projects I noticed that 32-byte seeds/secrets are hashed to arrive at new 32-byte keys.
The reason why is because you can then, with the addition to an index, use the same seed to generate multiple keypairs/addresses/wallets under one seed/secret.
For example:
seed1 = hash(seed,0); // abc..
seed2 = hash(seed,1); // def..
seed3 = hash(seed,2); // ghi..
Is this bad practice?
Is a unique secure 32-byte random seed for each keypair much better and worth the additional computation?
Or will you lose absolutely no entropy(?) by hashing a 32-byte value to a new 32-byte value?
(assuming for all of the above that the hash functions and keypair functions are secure)