The main limitation of using hash signature is that the receiver needs to hold a copy of the user's key to verify the signature, and there is the risk of key leakage and forged signature.

Hash signature is a common digital signature technology, which can be used to verify the integrity and authenticity of data. There are also some restrictions on using hash signatures. The receiver must hold a copy of the user's key to verify the signature, which means that the key will be exchanged during the signature process, and there is also the risk of being attacked during the key exchange process. Since both parties know the key to generate the signature, and the key is cracked, there will be a probability of forging the signature. Any central or user computer is breached, and its security is threatened. When using hash signature, we should pay attention to the security of the key and take corresponding security measures to protect the authenticity and integrity of the signature.