# Cryptic Cryptography

On the first day of my new job, I arrived to find a odd note on my desk.
It has a cryptic phrase and some jumbled letters.

"Reflection on the past gives insight into new angles of approach."

Crcuyseygmucxcg hc xyxwwwu abm yyfn! Lnj ciwa uhgkas mnjmkxqr gt t swxhjmuhkag mor alglbg zehmccxc hi ibm yyfn oa rhahewu abqb ikuzlq. Bb bfux mmx ng lvxwu vjo zug khbr ivawyd tgzyw olgc ei rhqqgtsuy dnjm fsb mehbccxc.

What could this possibly mean? Are my co-workers playing a prank on me?

Can you uncover the hidden message?

Using a vigenere cipher method: Always encrypt the next letter with the decrypted form of the previous one plus one. For example, if the last decrypted letter was C, use D as the next shift. For the first letter, just use a for no shift. So for the first word the key is adpohsbevmbujpo, which yields Congradulations.

The full key is
adpohsbevmbujpotpokpjojohuifufbnzpvibwfqspwfozpvstfmgbtbsftpvsdfgvmboexpsuizbeejujpoupuifufbncztpmwjohuijtqvaamfxfxjmmbmmcfhpjohpvugpstpnfesjoltbgufsxpslupdfmfcsbufzpvsofxqptjujp

The full decrypted plaintext is
Congradulations on joining the team! You have proven yourself as a resourceful and worthy addition to the team by solving this puzzle. We will all be going out for some drinks after work to celebrate your new position.

• Damn, I was trying exactly this but with the encrypted form. – Rand al'Thor Oct 4 '16 at 14:28
• nice work! haha but maybe the new guy will miss the drinks hahah – lois6b Oct 4 '16 at 14:52
• Nicely done. Not exactly the method I used, but you got the right answer so I'm marking it as correct. – R.R. Louw Oct 5 '16 at 8:11
• @R.R.Louw Interesting, I assume you used a ROT-X cipher for every letter, but where the letter is equal to the position in the latin alphabet, not the index (i.e. A=1, B=2, etc.))? This way the letter also wouldn't have to be increased by one place like in my solution. I only used the vigenere cipher because then the cipher could be decrypted at once, just with one key. – user14478 Oct 5 '16 at 8:38
• Exactly. At least for the encoding. So for the decoding one would have to use the inverse (i.e. encoding: Rot-4, decoding: Rot-22). – R.R. Louw Oct 5 '16 at 10:09