Time and Space complexity of MiniAES
The encryption process will use MiniAES which IS same as normal AES with all component reduced while maintaining the same structure and security of normal AES.

MiniAES most certainly does not have the same security as normal AES.  To quote the original paper:
It is meant to be a purely educational cipher and is not considered secure for
actual applications. 

Indeed, it has essentially zero security:

It has a 16 bit key.  It is trivial for an attacker to try all 65536 keys to search for the correct one.

It has a 16 bit block size; that means you'd hit he birthday bound after 512 encrypted bytes.

It doesn't reach full change propagation; an output nybble is a function of the key and two of the input nybbles (the other two input nybbles being irrelevent).  Hence, it can be characterized as two 8 bit block ciphers interleaved (hence you hit the birthday bound after encrypting only 32 bytes...)


It's sole reason for existence is to serve as target practice for budding cryptographers.