diff --git a/test/unit/test_watcher.py b/test/unit/test_watcher.py
index abbf59e..bf5d7dd 100644
--- a/test/unit/test_watcher.py
+++ b/test/unit/test_watcher.py
@@ -1,6 +1,8 @@
 import pytest
 from uuid import uuid4
+from hashlib import sha256
 from threading import Thread
+from binascii import unhexlify
 from queue import Queue, Empty
 
 from cryptography.hazmat.backends import default_backend
@@ -13,7 +15,7 @@ from pisa import c_logger
 from pisa.watcher import Watcher
 from pisa.responder import Responder
 from pisa.tools import check_txid_format, bitcoin_cli
-from test.unit.conftest import generate_block, generate_blocks, generate_dummy_appointment
+from test.unit.conftest import generate_block, generate_blocks, generate_dummy_appointment, get_random_value_hex
 from pisa.conf import EXPIRY_DELTA, PISA_SECRET_KEY, MAX_APPOINTMENTS
 
 c_logger.disabled = True
@@ -21,6 +23,7 @@ c_logger.disabled = True
 APPOINTMENTS = 5
 START_TIME_OFFSET = 1
 END_TIME_OFFSET = 1
+TEST_SET_SIZE = 200
 
 with open(PISA_SECRET_KEY, "r") as key_file:
     pubkey_pem = key_file.read().encode("utf-8")
@@ -34,6 +37,16 @@ def watcher(db_manager):
     return Watcher(db_manager)
 
 
+@pytest.fixture(scope="module")
+def txids():
+    return [get_random_value_hex(32) for _ in range(100)]
+
+
+@pytest.fixture(scope="module")
+def locator_uuid_map(txids):
+    return {sha256(unhexlify(txid)).hexdigest(): uuid4().hex for txid in txids}
+
+
 def create_appointments(n):
     locator_uuid_map = dict()
     appointments = dict()
@@ -171,3 +184,75 @@ def test_do_watch(watcher):
 
     assert len(watcher.appointments) == 0
     assert watcher.asleep is True
+
+
+def test_matches(watcher, txids, locator_uuid_map):
+    watcher.locator_uuid_map = locator_uuid_map
+    potential_matches = watcher.get_matches(txids)
+
+    # All the txids must match
+    assert locator_uuid_map.keys() == potential_matches.keys()
+
+
+def test_matches_random_data(watcher, locator_uuid_map):
+    # The likelihood of finding a potential match with random data should be negligible
+    watcher.locator_uuid_map = locator_uuid_map
+    txids = [get_random_value_hex(32) for _ in range(TEST_SET_SIZE)]
+
+    potential_matches = watcher.get_matches(txids)
+
+    # None of the txids should match
+    assert len(potential_matches) == 0
+
+
+def test_filter_valid_matches_random_data(watcher):
+    appointments = {}
+    locator_uuid_map = {}
+    matches = {}
+
+    for i in range(TEST_SET_SIZE):
+        dummy_appointment, _ = generate_dummy_appointment()
+        uuid = uuid4().hex
+        appointments[uuid] = dummy_appointment
+
+        locator_uuid_map[dummy_appointment.locator] = [uuid]
+
+        if i % 2:
+            dispute_txid = get_random_value_hex(32)
+            matches[dummy_appointment.locator] = dispute_txid
+
+    watcher.locator_uuid_map = locator_uuid_map
+    watcher.appointments = appointments
+
+    filtered_valid_matches = watcher.filter_valid_matches(matches)
+
+    assert not any([fil_match["valid_match"] for uuid, fil_match in filtered_valid_matches.items()])
+
+
+def test_filter_valid_matches(watcher):
+    dispute_txid = "0437cd7f8525ceed2324359c2d0ba26006d92d856a9c20fa0241106ee5a597c9"
+    encrypted_blob = (
+        "29f55518945408f567bb7feb4d7bb15ba88b7d8ca0223a44d5c67dfe32d038caee7613e35736025d95ad4ecd6538a50"
+        "74cbe8d7739705697a5dc4d19b8a6e4459ed2d1b0d0a9b18c49bc2187dcbfb4046b14d58a1add83235fc632efc398d5"
+        "0abcb7738f1a04b3783d025c1828b4e8a8dc8f13f2843e6bc3bf08eade02fc7e2c4dce7d2f83b055652e944ac114e0b"
+        "72a9abcd98fd1d785a5d976c05ed780e033e125fa083c6591b6029aa68dbc099f148a2bc2e0cb63733e68af717d48d5"
+        "a312b5f5b2fcca9561b2ff4191f9cdff936a43f6efef4ee45fbaf1f18d0a4b006f3fc8399dd8ecb21f709d4583bba14"
+        "4af6d49fa99d7be2ca21059a997475aa8642b66b921dc7fc0321b6a2f6927f6f9bab55c75e17a19dc3b2ae895b6d4a4"
+        "f64f8eb21b1e"
+    )
+
+    dummy_appointment, _ = generate_dummy_appointment()
+    dummy_appointment.encrypted_blob.data = encrypted_blob
+    dummy_appointment.locator = sha256(unhexlify(dispute_txid)).hexdigest()
+    uuid = uuid4().hex
+
+    appointments = {uuid: dummy_appointment}
+    locator_uuid_map = {dummy_appointment.locator: [uuid]}
+    matches = {dummy_appointment.locator: dispute_txid}
+
+    watcher.appointments = appointments
+    watcher.locator_uuid_map = locator_uuid_map
+
+    filtered_valid_matches = watcher.filter_valid_matches(matches)
+
+    assert all([fil_match["valid_match"] for uuid, fil_match in filtered_valid_matches.items()])