多项选择题
A. RC4 is a stream cipher B. Stream ciphers require padding C. AES is a block cipher D. DES and 3DES are stream ciphers E. AES is a stream cipher F. AES， DES， and 3DES can be used as HMAC algorithms
Whichofthefollowingstatementsaretrueregardinghashing？（）...
多项选择题Which of the following statements are true regardinghashing？ （）
A. MD5 produces a 160-bit result. B. SHA-256 is an extension to SHA-1 with a longer output. C. MD5 takes more CPU cycles to compute than SHA-1. D. Changing1 bit of the input to SHA-1 changes 1 bit of the output. E. SHA-1 is stronger than MD5 because it can be used with a key to prevent modification.
Whichtwostepsdoesareceiverperformtovalidateamessageusin...
多项选择题Which two steps does a receiver perform to validate a message using HMAC？ （）
A. decrypts the received MAC using a secret key B. compares the computed MAC vs. the MAC received C. authenticate the receivedmessage using the sender’s public key D. look up the sender’s public key E. extracts the MAC from the receivedmessage thenencrypts the received message with a secret keyto producethe MAC F. Computes the MAC using the receivedmessage and a secret key as inputs to the hash function
Whichofthefollowingbestdescribesahashfunction？（）A.An ir...
单项选择题Which of the following best describes a hash function？（）
A.An irreversible fast encryption method B.A reversible fast encryption method C.A reversible value computed from a piece of data and used to detect modifications D.An irreversible value computed froma piece of data and used to detect modifications E.A table inwhich values are stored for efficient retrieval.
