Certified Blockchain Developer Ethereum Flashcards
What is a sandbox?
A test environment that isolates untested code changes and experimentation from the production environment.
Name 4 characteristics of the EVM
1) Sandboxed VM
2) Runs on every node
3) Turing complete
4) Transaction based state machine
The blockchain is ………………. which means: The same input will always produce the same output.
Deterministic
What does hashing do with regards to hash size?
Map data of an arbitrary size to data of a fixed size.
Which hash function does Ethereum use?
Keccak-256 (which is like SHA256, but the two are NOT interchangeable)
List in order from lowest to highest the Ether denominations (up to one Ether)
Wei Kwai (Ada, Femtoether) Mwei (Babbage, picoether) Gwei (Shannon, nanoether, nano) Szabo (microether, micro) Finney (milliether, milli)
Kwei is also known as ………………. and ………………..
Ada
Femtoether
Mwei is also known as ……………… and ………………..
Babbage
Picoether
Gwei is also known as ………………. and ……………….
Shannon
Nanoether
Nano
What do you call 1000 ETH?
Kether
Grand
Einstein
What do you call 1 million ETH
Mether
What do you call a billion ETH?
Gether
What do you call a trillion ETH?
Tether
An ethereum address is bound to a ………………….
Private key
Describe an Ethereum address
64 character
32 bit hex value.
It is bound to the private key.
- The public key is derived from the private key
- The address is derived from the public key
What are the defining characteristics of POW?
mathematical riddle.
resource intensive
The input parameters for a hashed value has to be found
brute force, continuously hashing until the solution is found
Anyone can be a miner
What are the characteristics of POS?
There is no mining
Uses few resources
Stakeholders lock-in some money and are picked in a semi-random way to forge a new block
Anyone can be a forger
What is “stake” in the crypto world?
The cryptocurrency a user owns and pledges in order to partake in validation (POS)
How do Proof-of-Stake algorithms achieve consensus?
By requiring users to stake an amount of their tokens so as to have a chance of being selected to validate blocks of transactions, and get rewarded for doing so.
What is the incentive for good behaviour in a POS?
Payout in the form of transaction fees (as opposed to freshly created currency in PoW systems)
Name two types of account in the Ethereum network.
1) Externally owned accounts (EOS’s)
2) Smart contracts
An EOA is controlled by a ………………..
Private key (owned by an individual)
A Smart Contract has an …………….. of its own
Address
To send a transaction, which fields have to be set?
Nonce Gasprice Startprice To Value Data v,r,s
What is a replay attack?
A form of network attack in which a valid data transmission is maliciously or fraudulently repeated or delayed.
What is a nonce?
Nonce is a randomly-generated, cryptographic token that is used to prevent replay attacks.
In Ethereum, every transaction has a nonce. It is the number of transactions sent from a given address.
In cryptography is a one-time code selected in a random or pseudo-random manner that is used to securely transmit the main password, preventing a replay attack
Each time you send a transaction, the nonce increases by 1.
What is the notation for wei?
10^18