IBM Blockchain UPDATED ACTUAL Exam
Questions and CORRECT Answers
Which of the following blockchain use cases is an example of an Asset Exchange pattern? -
CORRECT ANSWER - b. Sharing of assets (voting, dividend notification)
[true/false] You can take a hash function and run it multiple times, so take the output of running
the hash function and use it as the input to the same hash function. This produces the same
results each time. - CORRECT ANSWER - . False
Staying with ROT13 as our hash function h, what is the output of running the following hash
chain? h("block" + h("chain")) - CORRECT ANSWER - b. oybpxchain
In a typical blockchain implementation, which of the following is an optional part of a block that
contains at least one transaction? - CORRECT ANSWER - c. Transaction data
Honest peer 1 thinks the world state is "abc". Honest peer 2 thinks the world state is "abc".
Honest peer 3 thinks the world state is "def". Malicious peer 4 wants everyone to believe that the
world state is "xyz". What is the optimal result of running a consensus algorithm against this
network? - CORRECT ANSWER - a. Peers 1, 2 and 3 think the world state is "abc". Peer
4 is ignored.
What might be considered data for the world state? - CORRECT ANSWER - a. Matt's
current balance
The ROT13 function takes an input string and converts any letters in it to those that are 13 ahead
of it in the alphabet, looping round as appropriate; so the input "blockchain" becomes
"oybpxpunva". ROT13 is not really an appropriate hash function, but which of these might be
considered an advantage of using it as a one-way hash function? - CORRECT ANSWER -
a. It is guaranteed to produce the same output for the same input.
Looking at the cryptocurrency market as a whole, which is the biggest differentiator between
cryptocurrency instances? - CORRECT ANSWER - a. The commodity being stored
, When considering token based blockchains vs. policy based blockchains, which of the following
is true? - CORRECT ANSWER - . Policy-based blockchains are permissioned according
to identity
[true/false] Ethereum is a distributed computing platform; it allows smart contracts to be run
globally. Crucially this gives us the concept of "guarantee of future execution" which we've
never had in computer science before; it ensures that code deployed as smart contracts *will* be
run. - CORRECT ANSWER - a. True
With so many existing blockchain implementations, which of the following is (are) key
indicator(s) of needs for blockchain standardization? - CORRECT ANSWER - d. All of
these
What does the "finality" quality of service provide to blockchain? - CORRECT
ANSWER - d. Transactions cannot be backed out
[true/false] In a traditional Blockchain example, Each participant keeps their own ledger(s)
which are updated to represent business transactions as they occur. - CORRECT
ANSWER - a. True
Which phrase best describes blockchain? - CORRECT ANSWER - a. Shared replicated
ledger
Which of the following statement is true about Bitcoin? [New] - CORRECT ANSWER - a.
Combination of Ledger and Asset
What does the "immutability" quality of service provide to blockchain? - CORRECT
ANSWER - An append-only data structure
Which of the following facts about ledgers is true? - CORRECT ANSWER - . Ledgers are
logs of transactions
Questions and CORRECT Answers
Which of the following blockchain use cases is an example of an Asset Exchange pattern? -
CORRECT ANSWER - b. Sharing of assets (voting, dividend notification)
[true/false] You can take a hash function and run it multiple times, so take the output of running
the hash function and use it as the input to the same hash function. This produces the same
results each time. - CORRECT ANSWER - . False
Staying with ROT13 as our hash function h, what is the output of running the following hash
chain? h("block" + h("chain")) - CORRECT ANSWER - b. oybpxchain
In a typical blockchain implementation, which of the following is an optional part of a block that
contains at least one transaction? - CORRECT ANSWER - c. Transaction data
Honest peer 1 thinks the world state is "abc". Honest peer 2 thinks the world state is "abc".
Honest peer 3 thinks the world state is "def". Malicious peer 4 wants everyone to believe that the
world state is "xyz". What is the optimal result of running a consensus algorithm against this
network? - CORRECT ANSWER - a. Peers 1, 2 and 3 think the world state is "abc". Peer
4 is ignored.
What might be considered data for the world state? - CORRECT ANSWER - a. Matt's
current balance
The ROT13 function takes an input string and converts any letters in it to those that are 13 ahead
of it in the alphabet, looping round as appropriate; so the input "blockchain" becomes
"oybpxpunva". ROT13 is not really an appropriate hash function, but which of these might be
considered an advantage of using it as a one-way hash function? - CORRECT ANSWER -
a. It is guaranteed to produce the same output for the same input.
Looking at the cryptocurrency market as a whole, which is the biggest differentiator between
cryptocurrency instances? - CORRECT ANSWER - a. The commodity being stored
, When considering token based blockchains vs. policy based blockchains, which of the following
is true? - CORRECT ANSWER - . Policy-based blockchains are permissioned according
to identity
[true/false] Ethereum is a distributed computing platform; it allows smart contracts to be run
globally. Crucially this gives us the concept of "guarantee of future execution" which we've
never had in computer science before; it ensures that code deployed as smart contracts *will* be
run. - CORRECT ANSWER - a. True
With so many existing blockchain implementations, which of the following is (are) key
indicator(s) of needs for blockchain standardization? - CORRECT ANSWER - d. All of
these
What does the "finality" quality of service provide to blockchain? - CORRECT
ANSWER - d. Transactions cannot be backed out
[true/false] In a traditional Blockchain example, Each participant keeps their own ledger(s)
which are updated to represent business transactions as they occur. - CORRECT
ANSWER - a. True
Which phrase best describes blockchain? - CORRECT ANSWER - a. Shared replicated
ledger
Which of the following statement is true about Bitcoin? [New] - CORRECT ANSWER - a.
Combination of Ledger and Asset
What does the "immutability" quality of service provide to blockchain? - CORRECT
ANSWER - An append-only data structure
Which of the following facts about ledgers is true? - CORRECT ANSWER - . Ledgers are
logs of transactions
