In the last article, a mysterious string was solved, but the key was missing.
U2FsdGVkX19Q3I//VCH0U3c
VtITZ3ckILJnUcdPX3Gs5qjdF
1UjZ3mAftGivtFYDN5ZCSkB
YnnVqBawl4p8wKO0O8zI6D0
A1+VEVCUyEvEeNoUfGcS0
El9d93vsPxbg7D5avufQsScg
Sk3QEtq9/M4Do32OKFeq00/
3NrxWOsMmh3AXmDzuuZ0
QmZaI7re16FcXIrmPPiQDO
HRc7wt0ng6qLiNz7VqESR
TdxPOahKFRkWT8sT+Ur2y
+2iZ2LEaxNM7UZqcPwYg
M6FoKOVjnqdeg30R27jc6
AoFPyRZ2g8+EJMp3n/
Pf94oSCLEWkc0osjH9D
QbM6DUptu3HJbAVwXQ==
Take a closer look at the 14-million-dollar bitcoin puzzle, which has five lines and a few letters and numbers scattered around it.
If you know how to do photoshop, you can cut out a few lines, flip the image horizontally, move the whole image in line with a few numbers, and get the picture below.
A line segment in the upper left connects L and 3, a line segment in the middle to the left connects 0 and 2, a line segment at the bottom is 9F, a line segment on the right connects three letters 5, 8 and 4, and a small circle outside the letter D indicates the number 7 symmetrically used.
Because there are no directions in the line, these letters and numbers may be arranged in reverse direction. There are 5 groups:
L3, 3L
02, 20 (here is the number 0, because the author who published the puzzle said no letter O).
9F, F9
584, 485
7
Using brute force method, write a C# program to generate all possible permutations and combinations, a total of 1920.
Because of the small amount of computation, the code is not optimized.
After you have the password, you need to try to decrypt the string "U2Fsd = =". OpenSSL tools are needed here. A key command line is:
OpenSSL enc -aes-256-cbc
-md MD5 -base64
-in "secret.txt" -d
-pass pass:L379F48502
That is to say, the string is encoded by Base64, and the encryption and decryption algorithm uses aes-256-cbc.
C# Code:
The key function is OpenSSLDecrypt (), which is found from the Internet.
Https://stackoverflow.com/questions/5452422/openssl-encryption-using-net-classes
Here we find a string of numbers that are very similar to the first pass and should also be a series of memorizing words.
511 B20 332328410530
245651 58F C2C 03A 717
401 9AC 36A 53F 4C6 B26
332328410530491312
Then 20181002 shift operations:
Remove the redundant 310, leaving the 12 set of sixteen binary values:
1C4 65F 38E 41C 018 70F 301 78C 2E9 53D 2C5 316
Convert to decimal system:
4521631910105224 180776919327451341 709790
The word "BIP39" converted to 12 words:
Debris slim immune lock
Actual tide gas vapor
Fringe pole flat glance
Unfortunately these mnemonics don't get the right wallet address. The author of the puzzle devised a trick to merge the previous 12 words into 24 words, and the wallet's private key appeared.
Cry buyer grain save
Vault sign lyrics rhythm
Music fury horror Mansion
Debris slim immune lock
Actual tide gas vapor
Fringe pole flat glance
Address:
1G7qsUy5x9bUd1pRfhVZ7cuB5cMUP4hsfR
Private key:
KxPEUpQ5BE75UGRUVjNmf8dQuWsmP9jqL3FUUjavdRW69MEcmg6C
Of course, 0.2 BTC has already been taken away.
Knowledge is money. You need to master the following skills in solving second problems:
Cutout of image editing
Permutation and combination
OpenSSL
Base64 coding
Sixteen metric computation
BIP39 mnemonic