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After my linear algebra lecture ended at 3:30 today, my friend passed me this note, but it seems to be encrypted in some way that I don't understand. What question is my friend asking, and what is the answer?

jjj

Feedback is appreciated, and I will add hints if necessary.

Hint 1:

There is a very good reason the characters look the way they do. It's not a simple substitution cipher.

Hint 2:

What does The class I'm Taking have To do with The cipher?

Riley
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  • Seems like a sub cipher... – NL628 Mar 24 '18 at 06:57
  • is it in english? – Jun Rikson Mar 24 '18 at 07:14
  • @ColourDalnet Yes, the cipher is in English. – Riley Mar 24 '18 at 09:03
  • if it is a substitution cipher, it looks like spaces may be substituted as well. there is a space at the end of the third line, implying that maybe the original string is literally each line placed end to end with no spaces in between, but that would leave a very long word at the end of line one beginning of line two. so, I think the space may be a cipher as well, and the actual spaces are encoded – Kae Verens Mar 24 '18 at 16:29
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    Does linear algebra have anything to do with the answer? – gsquaredxc Mar 25 '18 at 17:48
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    @GrantGarrison That is a good question. – Riley Mar 25 '18 at 17:54
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    im sure another good question would be about the significance of ending at 3:30 – tom Mar 26 '18 at 01:06
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    @tom I forget, was it 3:30 or 6:15? I always get the hour and minute hands mixed up :) – Riley Mar 26 '18 at 01:19
  • Are these characters somehow connected to the korean alphabet? Some of them look exactly like their syllables and consonants. – NAMELESS Mar 26 '18 at 04:01
  • Thinking about other languages is the wrong way to go. – Riley Mar 26 '18 at 04:47
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    All of the Ts in the second hint are capitolized. I am thinking we need to transpose the message. – Barker Mar 26 '18 at 21:25
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    Very nice puzzle, and great hints (especially those in the comments). They tread that fine line of being good enough to give a nudge in the right direction without making things too easy. – Phylyp Mar 27 '18 at 03:39
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    @Phylyp Thank you. This is my first cipher, so I didn't know exactly how it would go over. I like to do something more creative than some random combination of well-known ciphers (substitution, caesar, etc). Now, what should my next puzzle be... – Riley Mar 27 '18 at 03:50

2 Answers2

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First of all, great puzzle! I am currently in Linear Algebra myself.

As is hinted with the capitalization of 'T' in hint 2, we first take the transpose of the whole message
enter image description here

Then rewrite the message with the rows side by side.
enter image description here

This gives the outlines of block letters, which reads as: WHAT MATRIX OPERATION DID WE LEARN TODAY?

The answer to this is, of course, matrix transposition.

tyobrien
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1

Partial Answer:

The references to linear algebra and the capital Ts in the hint suggest that a transpose operation may be in order to read the message. I took the original image and transposed it as you would when taking the transpose of a matrix. The fact the letters are aligned to still make rows makes me think this may be the right track. transposed image

After getting this, with the new message I:

tried placing a unique letter to represent each symbol to use in a substitution cypher: 

abaz
acde
 aba
cdee
ywx 
afag
hecd
eafa
ia j
aja 
abah
 akh
caei
a de
fjac
la ?

Unfortunately, I didn't get anywhere with this.

Barker
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    Hmm, you might be onto something. :) But keep Hint 1 in mind. And one hint: The transpose of $\begin{bmatrix}8&8\8&8\end{bmatrix}$ is not $\begin{bmatrix}\infty&\infty\\infty&\infty\end{bmatrix}$ – Riley Mar 26 '18 at 22:09
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    Brilliant comment, @Riley :-) – Phylyp Mar 27 '18 at 03:05