# A valentine's code

Last Valentines Day, Harry received a card from an unknown person. As is tradition, he needed to figure out who it was. He suspects it is one of the following:

• Anna who has hinted she likes him.
• Lucy who is always shy around him.
• Jane who openly flirts with him.

However the card Harry received didn't have any clue to who it was. In fact, it didn't even contain any words. All it had was a picture of an old phone - one with a keypad and a small screen - on the front and the numbers:

1478914789633214789153698

• The actual answer to the question is of course that Harry should ask out whomever he happens to fancy, regardless of whether (s)he has written him a Valentine’s card or not. ;-) Nov 20, 2016 at 11:27

It was

Lucy

Because

Split the string like this: 14789 1478963 3214789 153698. Now draw lines between the digits of each part, using an oldschool keypad.

14789

1478963

3214789

153698

• Correct, I'll just wait for the image before accepting. Well done! Nov 19, 2016 at 21:50
• There we go! Well done Nov 19, 2016 at 22:02

Lukas Rotter's answer is the intended one, but in the spirit of Geobits SetBigO, I can't resist adding an alternative, more convoluted solution.

The card is from

Jane, who has made her interest clear but wants to test whether or not he returns her feelings.

• Since the card includes a picture of a phone with a keypad, it's clear that Harry should

map each number to a letter. For instance, 4 could map to G, H, or I. Making the appropriate choice in each case ('appropriate' being the one that yields a meaningful final answer), 1478914789633214789153698 becomes GQUW HPUWOFEC GQUW JEOYU.

• Given this string, he needs to

apply a Vigenere cipher to it. This is the true test of his affection: if his heart is set on Jane, he will try to think of ways to summarise her personality and interests. She's cute, funny, and her main interests are sumo wrestling and cello playing, so the key Harry should think of if he's into her is Cuty wit X sumo rowr celo J (her spelling isn't the best, unfortunately).

• Applying the key from the second step to the string found in the first step yields the message:

I LOVE YOU, HARRY - FROM JANE

Can't get much clearer than that!

• with the right one-time pad any viginere cypher can decrypt to anything. Nov 20, 2016 at 0:21
• Sorry for the downvote, but the middle step is just too weak. Nov 20, 2016 at 10:12

(Not a Cipher solution) The card is from

Lucy

Because

Lucy is shy, she wants to hide her feelings, so she hides it in a puzzle. Anna doesn't seem to care enough to think of something so elaborate, and Jane wouldn't need puzzles to show her feelings.