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.
相关考题
-
单项选择题
Whatdoesqospre-classifyprovidesinregardtoimplementingQoSoverGRE/IPSecVPNtunnels？（）
A. enables IOS to copy the ToS field from the inner （original） IPheader to theouter tunnel IP header
B. enables IOS to make a copy of the inner （original） IP header and to run a QoS classification before encryption， based on fields in the inner IP header.
C. enables IOS to classify packets based on the ToS field in the inner （original） IP header
D. enables IOS to classify packets based on the ToS field in the outer tunnel IP header
E. enables the IOS classification engine to only see a single encrypted and tunneledflow to reduce classification complexity -
多项选择题
Asymmetricandsymmetricciphersdifferinwhichofthefollowingway（s）？（）
A.Asymmetric ciphers use pre-shared keys
B.Symmetric ciphers are faster to compute
C.Asymmetric ciphers are faster to compute
D.Asymmetric ciphers use public and private -
单项选择题
WhichofthefollowingisthemosteffectivetechniquetopreventsourceIPAddressspoofing？（）
A. policy based routing （PBR）
B. unicast reverse path forwarding （uRPF）
C. lock and keyACL
D. RFC 1918filtering
E. IP source routing
