What are adventages and disadventages of encryption network security?

Network security focused on encryption are strong in raw computer security - the computers can encrypt data fast enough and the encryption is reliable and difficult to break. However, it has its downfalls - so called "backdoors" may be required in case of emergency but if found, they are a serious issue to security. The passwords created by users might be too simple and easy to break. They are also need to be sent though a network.