49 lines
3.4 KiB
Markdown
49 lines
3.4 KiB
Markdown
# 100 predictions
|
|
|
|
Para la versión en español, ve a [aquí](nunosempere.github.io/rat/100-predicciones)
|
|
|
|
## Day 1
|
|
{SHA is an acronym for "Secure Hashing Algorithm"; a hash algorithm recieves a string, or more generally a document, an returns a number.
|
|
Thus, a hash can identify a document, such that the hash can be revealed without revealing the document.
|
|
If the document is published afterwards, people know it hasn't been changed (because the hash would also change)
|
|
|
|
In 2017, a project by CWI Amsterdam and Google produced 2 different legible pdfs which had the same SHA1 hash.
|
|
This makes SHA1 insecure; it is no longer enough to uniquely identify a document.
|
|
|
|
The hash family continued with SHA2, and then SHA3. The most secure version of SHA3 is SHA-512.
|
|
|
|
Questions
|
|
- What probability, per year, do you assign to SHA-512 being successfully attacked?
|
|
By successfully attacked, we understand that someone finds x, x' such that SHA3-512(x) = SHA3-512(x'), or that given a
|
|
y = SHA3-512(z) someone finds a z' =/= z such that SHA3-512(z')=y.
|
|
- WHat probability, per year, do you assign to SHA3-512 being replaced as a standard?}
|
|
|
|
Recommended time: 15 mins.
|
|
|
|
## Day 2
|
|
{Elisabeth II, Queen of England, was born on 1926, whereas King Juan Carlos I of Spain was born on 1938.
|
|
|
|
Question:
|
|
- What probability do you assign to ELisabeth the II dying before Juan Carlos the I?
|
|
}
|
|
|
|
## Day 2 Discussion
|
|
In our group, probablities ranged from 4% (my own estimate) to 25%. I obtained my 6% figure going to (life tables)[https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/lifeexpectancies/datasets/nationallifetablesunitedkingdomreferencetables], and searching for life expectancies at 80 and 92 years old. I created a simplified model in which the queen of england was just an English peasant, ditto for the king of Spain.
|
|
With those tables in mind, it's relatively easy to calculate the probability that the queen will still ve alive in X years, and that the king will die in exactly X years. Multiplying both to get the probability of both events happening, and summing over all possible years, I arrive at a probability of 5,5575% for the statement under discussion. I adjust this upwards a little bit to 6%, because the queen seems healthier, the king broke his hip, and I'd guess the English Health system has better top notch doctors. If I really cared about the result, I might consider the rate of death not per year, but per week/month (interpolating those from the values at the beginning and end of each year), and would take into account rising life expectancies.
|
|
|
|
## Day 3
|
|
{The Effective Altruism Group in Spain wanted to give a TedX talk. What probability do you assign to one being given by the end of 2019? Pro tip: Consider the question in the negative: What probability do you assign to one NOT being given by the end of 2019?}
|
|
|
|
## Hashes
|
|
Everything between {} is hashed through SHA3-512 (https://www.browserling.com/tools/sha3-hash), and published on Twitter (@NunoSempere).
|
|
This, of course means that corrections or notes can't be made.
|
|
|
|
### Day 1
|
|
0addb6466a2fb3a537fa276e39306f2b57f8d31e66b826f57b62d141ff3de821fca5b9e35de06092c3847bc018b1531ecc3123e09b0f137700c2433b58f8781f
|
|
Notes: SHA-3 is replaced is interpreted as "SHA-4" is accepted as a standard.
|
|
|
|
### Day 2
|
|
3bb19d34fbb08347389f9d38cd5660235a5114df3890a052926d36988529b52fc3f72e27b00af88b1390b32591f54093d951abc7cbec94efb42f145d705786e0
|
|
|
|
### Day 3
|