Deck 15: Cryptographic Key Management and Distribution

Question 1

A major weakness of the public announcement of public keys is
that anyone can forge a public announcement.

Answer 1

True

Question 2

Manual delivery of a key is not reasonable for link encryption.

Answer 2

False

Question 3

For end-to-end encryption over a network, manual delivery is
awkward.

Answer 3

True

Question 4

the secure use of cryptographic key algorithms depends on the
protection of the cryptographic keys.

Question 5

__________ refers to the means of delivering a key to two parties who wish to exchange data, without allowing others to see the key.

A)Manual key delivery
B)Key distribution technique
C)Session key delivery
D)Confidentional key distribution

Question 6

For symmetric encryption to work the two parties to an exchange
must share the same key and that key must be protected from
access by others.

Question 7

the point of public-key encryption is that the public key is __________ .

A)public
B)private
C)confidential
D)restricted

Question 8

A common requirement in a variety of protocols is for the
encryption of a symmetric key so that it can be distributed to two parties for future communication.

Question 9

X.509 is an important standard because the certificate structure
and authentication protocols defined in X.509 are used in a
variety of contexts.

Question 10

__________ are often used to limit the time in which a key exchange can take place and/or the lifetime of an exchanged key.

A)Relay messages
B)Session breaks
C)timestamps
D)Keynotes

Question 11

A key translation center generates and distributes session keys.

Question 12

A certification authority is an authority trusted by one or more
users to create and assign public key certificates.

Question 13

A certificate consists of a public key, an identifier of the key owner,
and the whole block signed by a trusted third party.

Question 14

the term __________ refers to a key that is used only once or at most is very short-lived.

A)lower level key
B)digital key
C)cryptographic key
D)ephemeral key

Question 15

Because of the efficiency of public-key cryptosystems, they are
almost always used for the direct encryption of sizable blocks of dat
A.

Question 16

A greater degree of security can be achieved by maintaining a
publicly available dynamic directory of public keys.

Question 17

A __________ is a server or distributed set of servers that maintains a database of information about users.

A)crypt
B)directory
C)KDC
D)KtC

Question 18

Because certificates are forgeable they cannot be placed in a
directory without the need for the directory to make special
efforts to protect them.

Question 19

X.509 dictates the use of a specific digital signature algorithm and
a specific hash function.

Question 20

Each user must share a unique key with the key distribution center
for purposes of key distribution.

Question 21

With the __________ scheme, if an adversary succeeds in obtaining or computing the private key of the directory authority, the adversary could authoritatively pass out counterfeit public keys and subsequently impersonate any participant and eavesdrop on messages sent to any participant.

A)public key authority
B)publicly available directory
C)public key certificates
D)public announcement

Question 22

A _________ transfers symmetric keys for future communication between two entities, at least one of whom has the ability to generate or acquire symmetric keys by themselves.

Question 23

__________ indicates a restriction imposed as to the purposes for which, and the policies under which, the certified public key may be used.

A)Authority key identifier
B)Key usage
C)Subject key identifier
D)Certificate policies

Question 24

__________ is an integer value unique within the issuing CA that is unambiguously associated with this certificate.

A)Signature identifier
B)Version
C)Serial number
D)Issuer unique identifier

Question 25

the principal objective for developing a __________ is to enable secure, convenient, and efficient acquisition of public keys.

A)KtC
B)CRL
C)PKI
D)KDC

Question 26

the __________ identifies the public key to be used to verify the signature on this certificate or CRL.

A)authority key identifier
B)policy constraints
C)issuer name
D)directory

Question 27

Several techniques have been proposed for the distribution of public keys.the proposals can be grouped into the following four general schemes: public announcement, publicly available directory, public-key certificates, and ____________.

Question 28

A __________ generates and distributes session keys.

Question 29

Several techniques have been proposed for the distribution of public keys.the four proposals mentioned and discussed in the textbook are: Public announcement, Publicly available directory, Public-key authority, and _______ .

Question 30

One of the most important uses of a __________ cryptosystem is to encrypt secret keys for distribution.

A)master key
B)KDC
C)public key
D)end-to-end

Question 31

__________ is the process of administering or managing cryptographic keys for a cryptographic system.

Question 32

A __________ attack is when a protocol is insecure against an adversary who can intercept messages and can either relay the intercepted message or substitute another message.

Question 33

If encryption is done at the __________ level a key is needed for every pair of users or processes that require communication.

Question 34

the strength of any cryptographic system rests with the ___________ .

A)end encryption
B)key distribution technique
C)nonce
D)X.509 certificate

Question 35

the heart of the X.509 scheme is the __________ certificate associate with each user.

Question 36

the _________ can be an end user; a device such as a router or server; a process; or any item that can be identified in the subject name of a public key certificate.

A)repository
B)certification authority
C)end entity
D)registration authority

Question 37

X.509 is based on the use of public-key cryptography and __________ .

Question 38

If __________ is done at a network or IP level a key is needed for each pair of hosts on the network that wish to communicate.

A)end-to-end encryption
B)key management
C)key distribution
D)link encryption

Question 39

the principal objective for developing a _________ is to enable secure, convenient and efficient acquisition of public keys.

A)KDC
B)IEtF
C)PKI
D)CRL

Question 40

If A and B each has an encrypted connection to a third party C, C can deliver a key on the encrypted links to A and
B.A _________ center is responsible for distributing keys to pairs of users as needed.

Question 41

A _________ is any method for storing and retrieving PKI-related information, such as public key certificates and CRLs.

Question 42

A __________ consists of a public key, an identifier of the key owner, and the whole block signed by a trusted third party and can be used by participants to exchange keys without contacting a public key authority in a way that is as reliable as if the keys were obtained directly from a public key authority.

Question 43

A __________ is defined as a set of policies, processes, server platforms, software, and workstations used for the purpose of administering certificates and public-private key pairs, including the ability to issue, maintain, and revoke public key certificates.

Question 44

the __________ is an authority trusted by one or more users to create and assign public key certificates.

Question 45

the certificate extensions fall into three main categories: key and policy information, __________ , and certification path constraints.