A common method for creating a Verifiable Random Function is to hash the output of a digital signature scheme.  So if (sk,vk) is a key pair for a digital signature scheme, we can define a function: Fsk(x) = H( signsk(x) ).  Algorand implements a VRF like this using ED25519, and Ethereum’s RANDAO implements a VRF like this using BLS signatures.  What would be the problem with implementing this using ECDSA?

The following implements a simple “bank” that allows you to store and withdraw ETH.  What is wrong with this contract? contract Bank {   mapping(address => uint256) public balances;    function deposit(address _for) public payable {       balances += msg.value;   }   function withdraw(address from, uint256 amount) public {       require(balances >= amount, “insufficient balance”);       balances -= amount;       msg.sender.call{value: amount}(“”);   }}

What is a mitigation strategy for the approval vulnerability in ERC-20 tokens?

What is the purpose of a “faucet” in blockchain test networks?

Johnathan, 7 years and 6 months, participated in a speech and language evaluation. The SLP administered the CELF-5. Given the information below, formulate a paragraph explaining Johnathan’s performance on the CELF-5 in relation to the standardized test norming sample. Be sure to demonstrate your understanding of the normal distribution of scores, expected and unexpected scores, confidence intervals, etc.  Core Language Standard Score = 67 Percentile Rank = 1 Confidence Intervals: 68% +/- 3 90% +/- 5 95% +/- 7

Given the following information, formulate a paragraph describing Juan’s performance on the CELF-5 in relation to normal population: Standard Score Mean 90% CI 95% CI

________________ statistics can be used when the data is normally distributed.

In a normally distributed set of data, what percentage of data points will fall between +1 and -1 standard deviations? 

__________________ tells us the importance of a statistically significant finding. 

Given the following information, which statement is true?   Test scores were significantly higher when students studied for 5 hours as compared to 2 hours, p = .023, d = .8