diff -r c7d73e5840c8 -r 7342f5020691 share/hedgewars/Data/Scripts/OfficialChallenges.lua
--- a/share/hedgewars/Data/Scripts/OfficialChallenges.lua	Fri Feb 05 11:32:23 2016 +0300
+++ b/share/hedgewars/Data/Scripts/OfficialChallenges.lua	Mon May 01 13:59:24 2017 +0300
@@ -1,47 +1,63 @@
-function detectMap()
+local maps = {
+    ["Border,60526986531,M838018718Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #1"
+    , ["Border,71022545335,M-490229244Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #2"
+    , ["Border,40469748943,M806689586Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #3"
+    , ["85940488650,M-134869715Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #4"
+    , ["62080348735,M-661895109Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #5"
+    , ["56818170733,M479034891Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #6"
+    , ["Border,25372705797,M1770509913Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #7"
+    , ["Border,10917540013,M1902370941Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #8"
+    , ["Border,43890274319,M185940363Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #9"
+    , ["Border,27870148394,M751885839Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #10"
+    , ["Border,22647869226,M178845011Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #11"
+    , ["Border,46954401793,M706743197Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #12"
+    , ["Border,60760377667,M157242054Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #13"
+    , ["Border,51825989393,M-1585582638Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #14"
+    , ["81841189250,M256715557Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #15"
+    , ["Border,44246064625,M-528106034Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #16"
+    , ["60906776802,M-1389184823Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #17"
+    , ["Border,70774747774,M-534640804Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #18"
+    , ["Border,50512019610,M-1839546856Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #19"
+    , ["60715683005,M-281312897Scripts/Multiplayer/Racer.lua"] = "Racer Challenge #20"
+-- tech racer
+    , ["Border,19661006772,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #1"
+    , ["Border,19661306766,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #2"
+    , ["Border,19661606760,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #3"
+    , ["Border,19661906754,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #4"
+    , ["Border,19662206748,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #5"
+    , ["Border,19662506742,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #6"
+    , ["Border,19662806736,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #7"
+    , ["Border,19663106730,M-975391975Scripts/Multiplayer/TechRacer.lua"] = "Tech Racer #8"
+    }
+
+-- modified Adler hash
+local hashA = 0
+local hashB = 0
+local hashModule = 299993
+
+function resetHash()
+    hashA = 0
+    hashB = 0
+end
+
+function addHashData(i)
+    hashA = (hashA + i + 65536) % hashModule
+    hashB = (hashB + hashA) % hashModule
+end
+
+function hashDigest()
+    return(hashB * hashModule + hashA)
+end
+
+function detectMapWithDigest()
     if RopePercent == 100 and MinesNum == 0 then
--- challenges with border
+        mapString = hashDigest() .. "," .. LandDigest
+
         if band(GameFlags, gfBorder) ~= 0 then
-            if LandDigest == "M838018718Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #1")
-            elseif LandDigest == "M-490229244Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #2")
-            elseif LandDigest == "M806689586Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #3")
-            elseif LandDigest == "M1770509913Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #7")
-            elseif LandDigest == "M1902370941Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #8")
-            elseif LandDigest == "M185940363Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #9")
-            elseif LandDigest == "M751885839Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #10")
-            elseif LandDigest == "M178845011Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #11")
-            elseif LandDigest == "M706743197Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #12")
-            elseif LandDigest == "M157242054Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #13")
-            elseif LandDigest == "M-1585582638Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #14")
-            elseif LandDigest == "M-528106034Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #16")
-            elseif LandDigest == "M-534640804Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #18")
-            elseif LandDigest == "M-1839546856Scripts/Multiplayer/Racer.lua" then
-                return("Racer Challenge #19")
-            end
--- challenges without border
-        elseif LandDigest == "M-134869715Scripts/Multiplayer/Racer.lua" then
-            return("Racer Challenge #4")
-        elseif LandDigest == "M-661895109Scripts/Multiplayer/Racer.lua" then
-            return("Racer Challenge #5")
-        elseif LandDigest == "M479034891Scripts/Multiplayer/Racer.lua" then
-            return("Racer Challenge #6")
-        elseif LandDigest == "M256715557Scripts/Multiplayer/Racer.lua" then
-            return("Racer Challenge #15")
-        elseif LandDigest == "M-1389184823Scripts/Multiplayer/Racer.lua" then
-            return("Racer Challenge #17")
+            mapString = "Border," .. mapString
         end
+
+        --WriteLnToConsole(mapString)
+        return(maps[mapString])
     end
 end