   use ExUnit.Case, async: true
   doctest Matasano
 
+  @tag :set1
   test "set 1 challenge 1 - convert hex to base64" do
     hex = "49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d"
     base64 = "SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t"

    assert Matasano.hex_to_base64(hex) == base64
  end

  test "set 1 challenge 2 - fixed xor" do
    a = Base.decode16!("1c0111001f010100061a024b53535009181c", case: :lower)
    b = Base.decode16!("686974207468652062756c6c277320657965", case: :lower)

    assert Matasano.decrypt_single_byte_xor(ciphertext) == plaintext
  end

  @tag :set1
  test "set 1 challenge 4 - detect single-character xor" do
    data = Matasano.IO.lines_from_hex(Path.join("data", "4.txt"))
    plaintext = "Now that the party is jumping\n"
