01

Write-ups for TCTT2022/Crypto/01

Flag pattern

TCTT2022{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx}

Challenge Files

crypto-challenge01

Solution

1. Let scan this qr code.

And this is the result.

1337:101001001010110010000100100100001010001011101110100110101000100010000010101000101010110010010110101100101101101010001100110111101000001010000010101101001110011010110000111011101000010010110000100000101101100011010110100100101100010010000010101100101001000011001100100000101000001010001010110011001110111010000100110010001000011011011010110011101000001010110000110110101001101010010000101100101110111010100010100100001010111010100010101101001001111

2. I split it into 2 parts.

1337 and 101001001010110010000100100100001010001011101110100110101000100010000010101000101010110010010110101100101101101010001100110111101000001010000010101101001110011010110000111011101000010010110000100000101101100011010110100100101100010010000010101100101001000011001100100000101000001010001010110011001110111010000100110010001000011011011010110011101000001010110000110110101001101010010000101100101110111010100010100100001010111010100010101101001001111

3. Then let look at the second part.

101001001010110010000100100100001010001011101110100110101000100010000010101000101010110010010110101100101101101010001100110111101000001010000010101101001110011010110000111011101000010010110000100000101101100011010110100100101100010010000010101100101001000011001100100000101000001010001010110011001110111010000100110010001000011011011010110011101000001010110000110110101001101010010000101100101110111010100010100100001010111010100010101101001001111

It has 447 character, which is weird, so I added a 0 to the first letter to make it 8 bits convertable.

0101001001010110010000100100100001010001011101110100110101000100010000010101000101010110010010110101100101101101010001100110111101000001010000010101101001110011010110000111011101000010010110000100000101101100011010110100100101100010010000010101100101001000011001100100000101000001010001010110011001110111010000100110010001000011011011010110011101000001010110000110110101001101010010000101100101110111010100010100100001010111010100010101101001001111

4. Now we can convert it from binary to ascii.

5. The result it seem to BASE64, so let convert it.

6. Now, this is time for the first part 1337. We xor it with the result from the second part.

7. The result is tctt2022{QR_15_h1d1n9_50M37H1n9_1mP0R74n7}