In the first protocol of 
statistically binding and computationally concealing,
in order to commit a single classical bit
with security parameter $n$,
Bob needs to store only an $O((\log n)^3)$-bit quantum
string in our method, 
while an $n$-bit string in the classical standard method with the 
Goldreich-Levin hard-core predicate.
Notice that no quantum protocol is known for this purpose. 

In the second protocol of statistically concealing and computationally
binding, in order to commit $n$ classical bits simultaneously
with security parameter $n$,
Bob needs to store only an $O(n (\log n)^3)$-bit quantum
string in our method, 
while an $n^2$-bit quantum string in the previous quantum method 
by Dumais, Mayers, Salvail with $n$ parallel executions. 
Considering the rate, this scheme reduces exponentially 
the number of bits with Bob needs to store.