diff --git a/core/src/main/groovy/com/muwire/core/files/SearchIndex.groovy b/core/src/main/groovy/com/muwire/core/files/SearchIndex.groovy
new file mode 100644
index 00000000..0da0f3c8
--- /dev/null
+++ b/core/src/main/groovy/com/muwire/core/files/SearchIndex.groovy
@@ -0,0 +1,37 @@
+package com.muwire.core.files
+
+
+class SearchIndex {
+
+	final Map<String, Set<File>> keywords = new HashMap<>()
+	
+	void add(File f) {
+		String name = f.getName()
+		name = name.replaceAll("\\."," ")
+		String [] split = name.split(" ")
+		split.each {
+			Set<File> existing = keywords.get(it)
+			if (existing == null) {
+				existing = new HashSet<>()
+				keywords.put(it, existing)
+			}
+			existing.add(f)
+		}
+	}
+	
+	File[] search(List<String> terms) {
+		Set<File> rv = null;
+		
+		terms.each {
+			Set<File> forWord = keywords.get it
+			if (rv == null) {
+				rv = forWord
+			} else {
+				rv.retainAll(forWord)
+			}
+				
+		}
+		
+		rv.asList()
+	}
+}
diff --git a/core/src/test/groovy/com/muwire/core/files/SearchIndexTest.groovy b/core/src/test/groovy/com/muwire/core/files/SearchIndexTest.groovy
new file mode 100644
index 00000000..07b759db
--- /dev/null
+++ b/core/src/test/groovy/com/muwire/core/files/SearchIndexTest.groovy
@@ -0,0 +1,44 @@
+package com.muwire.core.files
+
+import org.junit.Test
+
+class SearchIndexTest {
+
+	SearchIndex index
+	
+	private void initIndex(List<String> entries) {
+		index = new SearchIndex()
+		entries.each {
+			File f = new File(it)
+			index.add(f)
+		}
+	}
+	
+	@Test
+	void testSingleTerm() {
+		initIndex(["a b.c", "d e.f"])
+		
+		def found = index.search(["a"])
+		assert found.size() == 1
+		assert found.contains(new File("a b.c"))
+	}
+	
+	@Test
+	void testSingleTermOverlap() {
+		initIndex(["a b.c", "c d.e"])
+		
+		def found = index.search(["c"])
+		assert found.size() == 2
+		assert found.contains(new File("a b.c"))
+		assert found.contains(new File("c d.e"))
+	}
+	
+	@Test
+	void testDrillDown() {
+		initIndex(["a b.c", "c d.e"])
+		
+		def found = index.search(["c", "e"])
+		assert found.size() == 1
+		assert found.contains(new File("c d.e"))
+	}
+}