Security is always determined by the number of points of failure/vulnerability. It is recommended to install PayCryptos on a dedicated corporate server isolated from the constant Internet access. In this case, the number of situations that can lead to hacking or loss of secret keys is reduced to a minimum. 

A personal computer can cause dangers since it may have viruses due to internet surfing on a regular basis or due to large number of users. 

A cloud solution, besides the external access, is risky because of situations when a user forgets to pay for the subscription and therefore loses all data.