What you are asking the participants to do is "decode" or "decipher" the text. As such, the "input" could be considered a code or a cipher.

Cipher - noun - secret or disguised way of writing; a code:

 

Usage: he was writing cryptic notes in a cipher

 

Usage: the information may be given in cipher

 

Alternate Definition: a thing written in a cipher.

 

Alternate Definition: a key to such a cipher.

or

Code - noun - system of words, letters, figures, or other symbols substituted for other words, letters, etc., especially for the purposes of secrecy:

 

Usage: the Americans cracked their diplomatic code

 

Usage: sending messages in code

What you are asking the participants to do is "decode" or "decipher" the text. As such, the "input" could be considered a code or a cipher.

Cipher - noun - secret or disguised way of writing; a code:

Usage: he was writing cryptic notes in a cipher

Usage: the information may be given in cipher

Alternate Definition: a thing written in a cipher.

Alternate Definition: a key to such a cipher.

or

Code - noun - system of words, letters, figures, or other symbols substituted for other words, letters, etc., especially for the purposes of secrecy:

Usage: the Americans cracked their diplomatic code

Usage: sending messages in code

What you are asking the participants to do is "decode" or "decipher" the text. As such, the "input" could be considered a cipher.

Cipher - noun - secret or disguised way of writing; a code:

Usage: he was writing cryptic notes in a cipher

Usage: the information may be given in cipher

Alternate Definition: a thing written in a cipher.

Alternate Definition: a key to such a cipher.

What you are asking the participants to do is "decode" or "decipher" the text. As such, the "input" could be considered a code or a cipher.

Cipher - noun - secret or disguised way of writing; a code:

Usage: he was writing cryptic notes in a cipher

Usage: the information may be given in cipher

Alternate Definition: a thing written in a cipher.

Alternate Definition: a key to such a cipher.

or

Code - noun - system of words, letters, figures, or other symbols substituted for other words, letters, etc., especially for the purposes of secrecy:

Usage: the Americans cracked their diplomatic code

Usage: sending messages in code