英譯漢
(1) 黑客（或稱電腦高手）就是指開發和重新設計計算機軟件和硬件，包括計算機程序的人。黑客還是個軟件設計師和程序開發師，可開發壹流的、美觀的程序及系統。
(2) 攻擊即對計算機系統或網絡的蓄意、智能襲擊行為。如，暴力破解，字典式破譯，“拒絕服務”攻擊，重放攻擊，捆綁式攻擊，以及滲透式攻擊或蓄意破壞。
(3) 網絡掃描即利用計算機網絡收集計算機系統上的信息，這些信息有可能被用來維護系統，系統安全系數評估和檢測，甚至用來攻擊系統。
（4）經過發送人用接收人的公***密匙把信息加密的信息只能通過接收人對應的個人密匙來破譯。
(5) 直至今天，密碼學所涉及的幾乎全是加密。加密就是把正常信息（純文本信息）轉化為難解或不可讀的信息的過程。這種不可讀信息被稱為密碼文體。解密則相反，把難懂的密碼文本轉成純文本。
(6) 在密碼學中，密碼哈希函數是指具有特定附加安全屬性以便作為各種信息安全應用的依據（primitive），如身份鑒定和信息的完整性。
(7) 對稱密匙密碼指信息發送者與接收者能***用同壹個密匙（或還有壹種比較少見的是，他們用不同的密匙但兩者可簡單計算關聯）的加密方法。
(8) 除了加密，公***密匙密碼還可用於實現數字簽名方案。數字簽名與普通的簽名相似，都有用戶操作簡單但他人難以模仿的特性。
漢譯英
(1) Active attack will cause the change of status and services of network system. Active attacks include attempts to block or break the protection mechanisms, to introduce malicious code, to steal or tamper the information. Active attacks may result in disclosure or dissemination of data, or result in denial of service and data tampering, including most of unauthorized users attempt to access to the remote system by ordinary or non-ordinary methods.
（2）Generally, a complete attack process is, the attacker is to hide himself first, then begin the pre-attack detection which is to detect the various properties of target machines and access what conditions are favorable for the attack; and then take the appropriate methods to carry out sabotage attacks, after succeed, attacker will delete their operations in the target system log.
（3）Denial of service (Dos in short) refers to an attempt to illegally accroach attacked target system’s service and unable the legal users to make use of it. The most common denial of service attack is the attacker to produce a large number of network packets and make them flow to victim network to consume all the available bandwidth of the network.
(4) A fundamental principle of modern cryptography is: all the secrets are kept in the key, which means when design the encryption systems, designers always assume that cryptographic algorithm is open; what really need to protect is the key. Because compared to the key, encryption algorithm is more likely to be leaked.
（5）Key of symmetric cryptosystem needs to be sent to receiver through a secure access by the sender. The advantages of cryptography are: high security, fast encryption speed; While the disadvantages are: the key management becomes a difficulty as network scale is growing; inextricability of message confirmation difficulty; lack of the ability to automatically detect the key leakage.
（6）Public-key cryptography is also called asymmetric-key cryptography. Every user who uses public- key cryptography has two keys: encryption key and decryption key. These two keys are different and further, it is infeasible to obtain the decryption key from the encryption key on the computer. Every user’s encryption key is public (and therefore, encryption key is also known as public-key).