Data encryption and decryption occurs at which layer of the OSI model？（）

Most ______ measures involve data encryption and password.

A．security

B．hardware

C．display

D．program

A.access control

B.encryption

C.data retrieving

D.data storing

E.auditing

A. symmetric key encryption

B. asymmetric key encryption

C. RSA

D. digital certificates

A. data integrity

B. encryption

C. key exchange

D. authentication

IDEA(International Data Encryption Algorithm)是由瑞士联邦工学院的Xuejia Lai 和James Massey 提出的一种()密码。

● Most （75） measures involve data encryption and password.

（75）

A. security

B. hardware

C. display

D. program

A.Fix Central

B.AIX 6.1 disc

C.IBM AIX Toolbox

D.AIX Expansion Pack

A. The same key is used for encryption and decryption.

B. It is commonly used to create digital certificate signatures.

C. It uses two keys: one for encryption and a different key for decryption.

D. An attacker can decrypt data if the attacker captures the key used for encryption.

A.Public keys must first be exchanged to enable data encryption, and then the system exchange host keys to enable authentication without passwords.

B.The system must exchange host keys to enable data encryption, and individual users must exchange public keys to enable authentication without passwords.

C.A key pair must be obtained from a CA to enable data encryption, then host keys must be exchanged to enable authentication.

D.A key pair must be obtained from a CA to enable authentication, then host keys must be exchanged to enable data encryption.

A. The same key is used for encryption and decryption.

B. It is commonly used to create digital certificate signatures.

C. It uses two keys: one for encryption and a different key for decryption.

D. An attacker can decrypt data if the attacker captures the key used for encryption.