Everyone knows that the Internet is very convenient. But in the past, the government could not serve the people on the Internet. There are two main reasons:

1. It is difficult to verify the identity of every person on the internet. (Impostors may fraudulently transfer land ownership and cause losses to other.)
2. There is a considerable risk when transmitting data over the internet without encryption. (For example, malicious hackers illegally steal data or accounts and passwords.)

The vast majority of government services currently require individuals, to personally present their ID card on site for processing.

The Citizen Digital Certificate contains the 'keys' obtained from asymmetric encryption algorithms, including the public key and the private key, and they are stored in the secure area of the physical IC card or mobile device. By using the certificate, one can perform digital signatures and identity verification. If the encryption and decryption function is enabled, the data will be encrypted, and even if intercepted, it can't be easily decrypted.

The three major functions of a Citizen Digital Certificate are as follow:

1. Identity verification: Based on public key infrastructure asymmetric encryption technology, a key is used to verify identity. When a user registers for a Citizen Digital Certificate, they are required to provide personal identification documents and other relevant information, which will be used to create a key containing a public key and a private key. It is because of the application and mutual verification of public and private keys that related application services can perform user identity verification.
2. Digital signatures: The Citizen Digital Certificate can be used to sign electronic documents, ensuring their integrity and non-repudiation. When verifying a digital signature, the public key should be used, while the private key should be used when creating a digital signature. Digital signature documents use hash algorithms, to create a unique, fixed-length message digest of the input message, ensuring the security of the digital signature. After sending the document, the recipient can use the signer's public key to verify the validity of the signature. Using a Citizen Digital Certificate for electronic document signing can effectively guarantee the integrity and non-repudiation of documents, as well as improve signing efficiency, reduce cumbersome manual signing processes, and ensure security.
3. Encryption and decryption: The principle of asymmetric encryption is used to protect the confidentiality of data. Citizen Digital Certificate have public and private keys. The private key is stored in a secure area of a physical IC card or mobile device and can't be extracted by any means. When you perform encryption operations, should use the public key, and perform decryption operations, should use the private key.

The Citizen Digital Certificate is not only a certificate, it is issued by the Certificate Authority of the Ministry of the Interior. After applying for a Citizen Digital Certificate, individuals can access various government e-services, such as Household Registration Online, File Taxes Online, National Health Insurance Personal Health Insurance Data Online Inquiry Service, Labor or Farmers Insurance Application Inquiry Service Online, which can reduce the risk of personal information leakage.

On February 16, 2022, the Citizen Digital Certificate application was upgraded to introduce the Mobile Citizen Digital Certificate App, which provides a Citizen Digital Certificate service that can be installed on mobile devices. Users can perform identity verification and digital signature functions through mobile devices such as smartphones or tablets. Users can access the relevant application services without the need to enter a password, by using biometric features such as facial recognition or fingerprint scanning for identification. Once verified, users can use the relevant application services. The use of Mobile Citizen Digital Certificate system eliminates the need for physical IC cards and card readers for Citizen Digital Certificate operations. With a mobile device, users can perform identity verification and digital signatures at any time and place, further enhancing the convenience of digitalization while maintaining the original level of security. To use the Mobile Citizen Digital Certificate for the first time, please register with a valid physical IC card for Citizen Digital Certificate at the website (URL: https://fido.moi.gov.tw/), and then download the Mobile Citizen Digital Certificate App from Google Play/App Store. After binding the mobile device such as smartphones or tablets, the service can be used.

The government has a lot of infrastructure services, but you are still asked to apply to enjoy the benefits of these infrastructure constructions. For example, if you want to enjoy the convenience of using electricity, you must first apply for an electricity meter; if you want to enjoy the convenience of tap water, you must first apply for a water meter; if you want to enjoy the convenience of applying for government business on the Internet, don't forget to apply for a Citizen Digital Certificate first. With a Citizen Digital Certificate, the internet is like a street, having a Citizen Digital Certificate is like carrying an online identification card. The government will work with you to achieve a high-quality online life.