diff --git a/modules/auth/src/main/scala/gs/smolban/auth/Argon2Hash.scala b/modules/auth/src/main/scala/gs/smolban/auth/Argon2Hash.scala
index 787be73..0c9cca6 100644
--- a/modules/auth/src/main/scala/gs/smolban/auth/Argon2Hash.scala
+++ b/modules/auth/src/main/scala/gs/smolban/auth/Argon2Hash.scala
@@ -1,6 +1,7 @@
 package gs.smolban.auth
 
 import java.util.Base64
+import java.util.Objects
 import scala.util.Try
 
 /** Represents an Argon2 hash packed with the parameters that produced it.
@@ -30,6 +31,30 @@ final class Argon2Hash(
   val hash: Array[Byte]
 ):
 
+  override def equals(obj: Any): Boolean =
+    obj match
+      case other: Argon2Hash =>
+        (algorithmVersion == other.algorithmVersion)
+        && (algorithmType == other.algorithmType)
+        && (iterations == other.iterations)
+        && (parallelism == other.parallelism)
+        && (memoryInKb == other.memoryInKb)
+        && (salt.sameElements(other.salt))
+        && (hash.sameElements(other.hash))
+
+  override def hashCode(): Int =
+    Objects.hash(
+      algorithmVersion,
+      algorithmType,
+      iterations,
+      parallelism,
+      memoryInKb,
+      salt,
+      hash
+    )
+
+  override def toString(): String = encode()
+
   /** Encode this hash as a '$' delimited string that includes all parameters.
     * This string can be parsed by using the `decode` function.
     *
@@ -37,7 +62,7 @@ final class Argon2Hash(
     *   The encoded hash string.
     */
   def encode(): String =
-    s"v=$algorithmVersion$$t=$algorithmType$$i=$iterations$$p=$parallelism$$m=$memoryInKb}$$${encodedSalt()}$$${encodedHash()}"
+    s"v=$algorithmVersion$$t=$algorithmType$$i=$iterations$$p=$parallelism$$m=$memoryInKb$$${encodedSalt()}$$${encodedHash()}"
 
   private def encodedSalt(): String =
     Base64.getEncoder().encodeToString(salt)
diff --git a/modules/auth/src/test/scala/gs/smolban/auth/Argon2Tests.scala b/modules/auth/src/test/scala/gs/smolban/auth/Argon2Tests.scala
new file mode 100644
index 0000000..8734fe8
--- /dev/null
+++ b/modules/auth/src/test/scala/gs/smolban/auth/Argon2Tests.scala
@@ -0,0 +1,70 @@
+package gs.smolban.auth
+
+import cats.effect.IO
+import cats.effect.unsafe.IORuntime
+import munit.Location
+import org.bouncycastle.crypto.params.Argon2Parameters
+
+class Argon2Tests extends munit.FunSuite:
+  given IORuntime = IORuntime.global
+
+  def iotest(
+    name: String
+  )(
+    f: => IO[Unit]
+  )(
+    using
+    Location
+  ): Unit =
+    test(name)(f.unsafeRunSync())
+
+  val rng: RandomByteProvider[IO] = RandomByteProvider.secureRandom[IO]
+
+  val altConfig: Argon2.Config = Argon2.Config(
+    algorithmVersion = Argon2Parameters.ARGON2_VERSION_10,
+    algorithmType = Argon2Parameters.ARGON2_i,
+    iterations = 2,
+    parallelism = 1,
+    memoryInKb = 1024,
+    saltLengthInBytes = 8,
+    hashLengthInBytes = 64
+  )
+
+  iotest("should calculate a hash and verify against that hash") {
+    val input = "some Complex password!1"
+    for
+      secret  <- Argon2Secret.generate(32, rng)
+      argon2  <- IO(new Argon2[IO](Argon2.defaultConfig(), secret, rng))
+      hash    <- argon2.calculateHash(input)
+      matched <- argon2.doesInputMatch(input, hash)
+      encoded <- IO(hash.encode())
+      decoded <- IO(Argon2Hash.decode(encoded))
+    yield
+      assertEquals(matched, true)
+      assertEquals(hash.algorithmType, Argon2.Defaults.AlgorithmType)
+      assertEquals(hash.algorithmVersion, Argon2.Defaults.AlgorithmVersion)
+      assertEquals(hash.iterations, Argon2.Defaults.Iterations)
+      assertEquals(hash.parallelism, Argon2.Defaults.Parallelism)
+      assertEquals(hash.memoryInKb, Argon2.Defaults.MemoryInKB)
+      assertEquals(Some(hash), decoded)
+  }
+
+  iotest("should match using stored params, not configured params") {
+    val input = "Another super s3cr3t pass@"
+    for
+      secret    <- Argon2Secret.generate(32, rng)
+      altArgon2 <- IO(new Argon2[IO](altConfig, secret, rng))
+      defArgon2 <- IO(new Argon2[IO](Argon2.defaultConfig(), secret, rng))
+      altHash   <- altArgon2.calculateHash(input)
+      // We're using the default configuration to run the match, and it should
+      // still match because we have the same secret and the params are
+      // extracted from the hash rather than the configuration.
+      matched <- defArgon2.doesInputMatch(input, altHash)
+    yield
+      assertEquals(matched, true)
+      assertEquals(altHash.algorithmType, altConfig.algorithmType)
+      assertEquals(altHash.algorithmVersion, altConfig.algorithmVersion)
+      assertEquals(altHash.iterations, altConfig.iterations)
+      assertEquals(altHash.parallelism, altConfig.parallelism)
+      assertEquals(altHash.memoryInKb, altConfig.memoryInKb)
+  }