SHA-1 is the most commonly used SHA algorithm, and produces a ______-byte hash value(size).
D
Explanation:
SHA-1 is the most commonly used SHA algorithm, and produces a 20-byte hash value.
What type of attack would be considered a very large flaw in public blockchains such as Bitcoin’s
Blockchain where the majority of hashpower could possibly be controlled thru an attack?
What is the specific attack Bitcoin could be exposed to?
A
How many satoshis are in 1 bitcoin and how many wei in an Ether? (Select two.)
A,B
In the Proof of Stake(POS) algorithm the miners are really known as ___________?
C
Explanation:
Proof of Stake has the same goal as proof of work—to validate transactions and achieve consensus in
the chain—and it uses an algorithm but with a different process. With proof of stake, the creator of a
new block “is chosen in a deterministic way, depending on its wealth, also defined as a stake.” Since
in a proof of stake system, there is no block reward, but the miners, known as forgers, get the
transaction fees. Proponents of this shift, including Ethereum co-founder Buterin, like proof of stake
for the energy and cost savings realized to get to a distributed form of consensus.
A Byzantine failure is the loss of a system service due to a Byzantine fault in systems that
requires________.
What is required?
A
Explanation:
A Byzantine failure is the loss of a system service due to a Byzantine fault in systems that require
consensus.
A ____________cipher basically means it is using a fixed key which replaces the message with a
pseudorandom string of characters. It is basically the encryption of each letter one at a time.
What is the cipher type?
A
Explanation:
Stream cipher basically means using a fixed key which replaces the message with a pseudorandom
string of characters. It is basically the encryption of each letter one at a time.
You currently using the Metamask Chrome plugin and you see a selection for Etherescan in the
plugin.
What is Etherscan used for?
A
Explanation:
A search engine that allows users to easily lookup, confirm and validate transactions that have taken
place on the Ethereum Blockchain
What are two challenges with using a Proof of Work algorithm? (Select two.)
C,D
Your customer is an enterprise that is focused on financial sectors.
What type of blockchain would this customer likely want specified for their enterprise?
D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to
access any or parts of that blockchain. There are a multitude of variants and hybrid
permissioned/permissionless blockchains that exist.
Which is the following is the metaphor that describes a logical dilemma that plagues many computer
networks?
B
Explanation:
BFT is so-named because it represents a solution to the "Byzantine generals' problem," a logical
dilemma that researchers Leslie Lamport, Robert Shostak and Marshall Pease described in an
academic paper published in 1982
The key difference between encryption and hashing is that encrypted strings can be reversed back
into their original decrypted form if you have the right key?
A
What is a logic gate in electronics and computer science?
D
Explanation:
A logic gate usually takes in 2 inputs and gives out 1 output. The inputs and outputs are binary
values, meaning they can be 1 or 0. A XOR logic gate takes in 2 binary inputs and gives out a high
output ONLY when the inputs are different. Meaning, if A and B are inputted to a XOR gate then the
out C will be 1 ONLY when A is not equal to B.
Ethereum is considered to be a ______________type of blockchain.
A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a
wallet and write data onto and transact within the blockchain (as long as they follow the rules of the
bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.
Your company working for is now considering the blockchain. They would like to perform a POC with
R3 Cord
a. The CIO was reading about different blockchain consensus algos and would like to understand
what type of consensus algos is used with Corda.
What is the best answer?
A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over
transaction finality and we need to know who our counterparts are. So we had the freedom – and
took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves
the privacy issue in a number of manners, primarily by allowing for separation of consensus into a
service which we call the Notary Cluster. Corda was designed for business from the start. It has no
cryptocurrency built into the platform and does not require mining-style consensus, which imposes
great cost with little business benefit.
Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the
length of the input (even if input is millions of bytes). Select best answer.
D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will
always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless
of the length of the input (even if input is millions of bytes).