To understand the function of WS-Security, we can first look at similar situations in real life. Specifically, when and how do you use documents in your daily life? After all, daily life is always inseparable from various documents. If someone asks you to prove your age, you will take out your ID card from your wallet. If you don't pay in cash, you will use a credit card to prove your identity to the lender. When crossing the border or going abroad, you need to prove your identity with your passport. These are all documents. Its function is to show that the owner of credit card, driver's license and passport is consistent with the person on the certificate. But they won't verify your identity. Authentication is a behavior, and the certificate itself cannot implement this behavior. When using written documents, people are the executors of authentication. So how is the verification process realized?

When you show your driver's license or passport, the inspector will do something to verify whether the documents are authentic and whether you are the legal owner of these documents: both documents contain the photo of the registered holder of the documents and other identity characteristics: height, weight and eye color. The person reading the certificate can ensure that you are consistent with the person shown and described in the certificate. The certificate has a certain validity period. This can ensure that the description data in the certificate is the latest data. A certificate contains a signature that can be compared with the signature of the person who presented the certificate. It is difficult to imitate the signature of others accurately, so combined with the description of the certificate holder, the certificate becomes a reasonable authentication method. These documents have other important features. The mark on the certificate can make people quickly verify the authenticity of the certificate. Certificates are issued by institutions we trust that can provide valid identity information: local or national governments. It also mentioned credit cards. It is different from driver's license and passport. They are issued by banks rather than the government. They only contain the signature and name used to identify the cardholder. They can only be used for identity verification when presenting other supporting documents (such as government-issued identity cards). So what can certificates like credit cards do?

Credit cards usually rely only on signatures for authentication. Some credit cards carry photos to increase the reliability of authentication. Due to the insufficient authentication provided by credit cards, many institutions require government-issued ID to be provided together with credit cards. As far as security is concerned, when you show your credit card, you are declaring that you have the right to buy goods and services, and the institution that provides you with the credit card will pay the merchant. Merchants can confirm that you are a valid cardholder by comparing their ID cards with photos issued by the government. (Of course, if the transaction is made by telephone or online, it is another matter, but it also shows that there are other security mechanisms in these fields. )