Science Olympiad at MIT Invitational 2019

[Name]

Did anyone try the RSA on the code test? I'm pretty sure they encoded it wrong by grouping it together. Then they modded it (?????) which seems to be even more wrong. Finally n is suppose to be the product of 2 primes and 96 is definitely not the product of 2 primes.

[Unome]

A random note - I don't think I mentioned it on the answer key, but the maps used in the Geomaps test were excerpts from the Electra Lake quadrangle in Colorado (Section F), and the Jordan Narrows quadrangle in Utah (Section L). I believe both were 7.5 minute, although I don't remember for sure.

[pepperonipi]

Did anyone try the RSA on the code test? I'm pretty sure they encoded it wrong by grouping it together. Then they modded it (?????) which seems to be even more wrong. Finally n is suppose to be the product of 2 primes and 96 is definitely not the product of 2 primes.

How did you go about solving this? It seems like the test maker was somewhat on track (the equation is , where is the message and is the cipher text). However, I think they did , which I don't believe is valid.

Modding it is okay for the RSA Cipher, and you are definitely supposed to do it. If you didn't you would have insanely large numbers with longer messages (like "trees").

[Name]

Did anyone try the RSA on the code test? I'm pretty sure they encoded it wrong by grouping it together. Then they modded it (?????) which seems to be even more wrong. Finally n is suppose to be the product of 2 primes and 96 is definitely not the product of 2 primes.

How did you go about solving this? It seems like the test maker was somewhat on track (the equation is , where is the message and is the cipher text). However, I think they did , which I don't believe is valid.

Modding it is okay for the RSA Cipher, and you are definitely supposed to do it. If you didn't you would have insanely large numbers with longer messages (like "trees").

So TREES is 19174418. They took the mod 96 of this which is 50, and they encoded 50 into 32. But when you decode 32 you would get 50 and you might as well encrypted the word OG (146) which mod 96 is also 50. It would make more sense instead to encode each letter seperately.
We didn't actually try solving this, it was worth only 200 pts so we focused on other questions.

[pepperonipi]

Did anyone try the RSA on the code test? I'm pretty sure they encoded it wrong by grouping it together. Then they modded it (?????) which seems to be even more wrong. Finally n is suppose to be the product of 2 primes and 96 is definitely not the product of 2 primes.

How did you go about solving this? It seems like the test maker was somewhat on track (the equation is , where is the message and is the cipher text). However, I think they did , which I don't believe is valid.

Modding it is okay for the RSA Cipher, and you are definitely supposed to do it. If you didn't you would have insanely large numbers with longer messages (like "trees").

So TREES is 19174418. They took the mod 96 of this which is 50, and they encoded 50 into 32. But when you decode 32 you would get 50 and you might as well encrypted the word OG (146) which mod 96 is also 50. It would make more sense instead to encode each letter seperately.
We didn't actually try solving this, it was worth only 200 pts so we focused on other questions.

Yeah, I think RSA is supposed to prevent things like this if it's done correctly. However, like you said earlier, 96 isn't the product of 2 primes, which I think is screwing the whole system up if you were to decode.

And like you said, it really wasn't worth contemplating a lot of time over since it was only 200 points. In the future I would have just attempted it using the encryption formula and not bothered wondering about decryption/encryption problems so that other problems could be focused on. If you knew the formula and used it right, it easily could've taken you 2 minutes or so. But then again, that would only be if the writer also used the equation right lol.

Also, congrats on the first.

[Name]

How did you go about solving this? It seems like the test maker was somewhat on track (the equation is , where is the message and is the cipher text). However, I think they did , which I don't believe is valid.

Modding it is okay for the RSA Cipher, and you are definitely supposed to do it. If you didn't you would have insanely large numbers with longer messages (like "trees").

So TREES is 19174418. They took the mod 96 of this which is 50, and they encoded 50 into 32. But when you decode 32 you would get 50 and you might as well encrypted the word OG (146) which mod 96 is also 50. It would make more sense instead to encode each letter seperately.
We didn't actually try solving this, it was worth only 200 pts so we focused on other questions.

Yeah, I think RSA is supposed to prevent things like this if it's done correctly. However, like you said earlier, 96 isn't the product of 2 primes, which I think is screwing the whole system up if you were to decode.

And like you said, it really wasn't worth contemplating a lot of time over since it was only 200 points. In the future I would have just attempted it using the encryption formula and not bothered wondering about decryption/encryption problems so that other problems could be focused on. If you knew the formula and used it right, it easily could've taken you 2 minutes or so. But then again, that would only be if the writer also used the equation right lol.

Also, congrats on the first.

Thanks!

[waterqualityquestion]

Does anyone know when the picture album is available (like the medal/trophy pictures) and where I would be able to access it?

[mdv2o5]

Does anyone know when the picture album is available (like the medal/trophy pictures) and where I would be able to access it?

All the post-tournament stuff is on their website: http://scioly.mit.edu/updates/index.html.

[Name]

Has anyone else never recieved tests/medals back yet? It's been almost a month, and we don't have them yet. We've also recieved no response yet when emailing them.

[C8H10N4O2!]

Has anyone else never recieved tests/medals back yet? It's been almost a month, and we don't have them yet. We've also recieved no response yet when emailing them.

I was wondering the same thing...