题干：机密数据能够安全地在互联网上发送通过使用
A.数字签名。
B.防火墙。
C.加密。
D.单次使用的密码
考点：Internal Controls -- Internal Auditing and Systems Controls-Systems Controls
关键词：transfer on internet
解题思路：如果要在互联网上发送数据，那么最有效的方法就是给数据加密
A digital signature is an electronic signature that can be used to authenticate the identity of the sender of a message or the signer of a document. It can also be used to ensure that the original content of the message or document that was sent has not been changed. The ability to ensure that the original signed message arrived means that the sender cannot easily say later that he never sent it or that he sent something different. A digital signature can be used with any kind of message, whether it is encrypted or not, so that the receiver can be sure of the sender's identity and that the message arrived without being changed. However, a digital signature does not provide security for confidential data that is being sent over the internet, because it does not prevent the data from being intercepted while being transmitted.
A firewall serves as a barrier between the internal and the external networks and prevents unauthorized access to the internal network. It does not enable confidential data to be securely transmitted over the internet, because it does not prevent the data from being intercepted while being transmitted.
Encryption is the best protection against internet traffic being intercepted, resulting in data leaks. Encryption converts data into a code, and then a key is required to convert the code back to data. Unauthorized people can receive the coded information, but without the proper key, they cannot read it. Thus, an attacker may be able to see where the traffic came from and where it went but not the content.
A single-use password is a password that is valid for only one login session or transaction. If an intruder manages to intercept a single-use password that has already been used to log into a service or to conduct a transaction, he or she will not be able to use it again, because it will no longer be usable. Single-use passwords do not enable confidential data to be securely transmitted over the internet, however, because they do not prevent the data from being intercepted while being transmitted.
