diff --git a/go.mod b/go.mod
index fcb6e13..7d0bf24 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module git.openprivacy.ca/openprivacy/connectivity
 go 1.13
 
 require (
+	filippo.io/edwards25519 v1.0.0-rc.1
 	git.openprivacy.ca/openprivacy/bine v0.0.4
 	git.openprivacy.ca/openprivacy/log v1.0.2
 	golang.org/x/crypto v0.0.0-20201012173705-84dcc777aaee
diff --git a/go.sum b/go.sum
index 3541254..f9bd8bf 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,5 @@
+filippo.io/edwards25519 v1.0.0-rc.1 h1:m0VOOB23frXZvAOK44usCgLWvtsxIoMCTBGJZlpmGfU=
+filippo.io/edwards25519 v1.0.0-rc.1/go.mod h1:N1IkdkCkiLB6tki+MYJoSx2JTY9NUlxZE7eHn5EwJns=
 git.openprivacy.ca/openprivacy/bine v0.0.4 h1:CO7EkGyz+jegZ4ap8g5NWRuDHA/56KKvGySR6OBPW+c=
 git.openprivacy.ca/openprivacy/bine v0.0.4/go.mod h1:13ZqhKyqakDsN/ZkQkIGNULsmLyqtXc46XBcnuXm/mU=
 git.openprivacy.ca/openprivacy/log v1.0.2 h1:HLP4wsw4ljczFAelYnbObIs821z+jgMPCe8uODPnGQM=
diff --git a/tor/torUtils.go b/tor/torUtils.go
index cd4c233..e210be4 100644
--- a/tor/torUtils.go
+++ b/tor/torUtils.go
@@ -3,6 +3,7 @@ package tor
 import (
 	"encoding/base32"
 	"errors"
+	"filippo.io/edwards25519"
 	"git.openprivacy.ca/openprivacy/bine/control"
 	"git.openprivacy.ca/openprivacy/bine/tor"
 	"golang.org/x/crypto/ed25519"
@@ -45,6 +46,33 @@ func IsValidHostname(address string) bool {
 		data, err := base32.StdEncoding.DecodeString(strings.ToUpper(address))
 		if err == nil {
 			pubkey := data[0:ed25519.PublicKeySize]
+
+			// Tor won't allow us to connect to a hostname containing a torsion component
+			// However because we permit authentication over inbound connections we would like to
+			// be extra safe and reject all *invalid* hostnames that contain a torsion component...
+
+			// to do this we need to multiply the point by the order of the group and check that the
+			// result is the ed25519 identity element.
+			// l = order of the group (minus 1)
+			lBytes := []byte{236, 211, 245, 92, 26, 99, 18, 88, 214, 156, 247, 162, 222, 249, 222, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16}
+			l, _ := edwards25519.NewScalar().SetCanonicalBytes(lBytes)
+
+			// construct a curve point from the public key
+			// if this fails then the hostname is invalid
+			p, err := new(edwards25519.Point).SetBytes(pubkey)
+			if err != nil {
+				return false
+			}
+
+			// Calculate l*P (actually (l-1)P + P because of the limitations of the scalar library...
+			result := new(edwards25519.Point).ScalarMult(l, p)
+			result = new(edwards25519.Point).Add(result, p)
+			// The result should be the identity point..assuming the hostname contains no torsion components...
+			if result.Equal(edwards25519.NewIdentityPoint()) == 0 {
+				return false
+			}
+
+			// Finally check that we arrive at the same hostname as the one we were given...
 			if GetTorV3Hostname(ed25519.PublicKey(pubkey)) == address {
 				return true
 			}
diff --git a/tor/torUtils_test.go b/tor/torUtils_test.go
index e5bc476..0416c2a 100644
--- a/tor/torUtils_test.go
+++ b/tor/torUtils_test.go
@@ -1,6 +1,9 @@
 package tor
 
 import (
+	"encoding/hex"
+	"filippo.io/edwards25519"
+	"git.openprivacy.ca/openprivacy/bine/torutil"
 	"os"
 	"testing"
 )
@@ -13,6 +16,79 @@ func TestGenerateHashedPassword(t *testing.T) {
 	}
 }
 
+func TestIsValidHostname(t *testing.T) {
+	openprivonion := "openpravyvc6spbd4flzn4g2iqu4sxzsizbtb5aqec25t76dnoo5w7yd"
+	t.Logf("testing: %v", openprivonion)
+	if IsValidHostname(openprivonion) == false {
+		t.Fatalf("open privacy onion should validate as a valid hostname")
+	}
+
+	sarahonion := "icyt7rvdsdci42h6si2ibtwucdmjrlcb2ezkecuagtquiiflbkxf2cqd"
+	t.Logf("testing: %v", sarahonion)
+	if IsValidHostname(sarahonion) == false {
+		t.Fatalf("sarah onion should validate as a valid hostname")
+	}
+
+	// First we will construct a torsion point from our Valid Onion
+	pubKey, _ := torutil.PublicKeyFromV3OnionServiceID(openprivonion)
+	pubKeyPoint, _ := new(edwards25519.Point).SetBytes(pubKey)
+	torsionPubKeyBytes, _ := hex.DecodeString("26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc05")
+	torsionHostname, _ := torutil.PublicKeyFromV3OnionServiceID(GetTorV3Hostname(torsionPubKeyBytes))
+	torsionPoint, _ := new(edwards25519.Point).SetBytes(torsionHostname)
+	malformedKey := new(edwards25519.Point).Add(pubKeyPoint, torsionPoint)
+
+	t.Logf("testing: %v", GetTorV3Hostname(malformedKey.Bytes()))
+	if IsValidHostname(GetTorV3Hostname(malformedKey.Bytes())) == true {
+		t.Fatalf("torsion onion should not validate as a valid hostname")
+	}
+
+	// Testing a few torsion points taken from https://lists.torproject.org/pipermail/tor-dev/2017-April/012226.html
+	torsionPubKey, _ := hex.DecodeString("0000000000000000000000000000000000000000000000000000000000000000")
+	t.Logf("testing: %v", GetTorV3Hostname(torsionPubKey))
+	if IsValidHostname(GetTorV3Hostname(torsionPubKey)) == true {
+		t.Fatalf("torsion onion should not validate as a valid hostname")
+	}
+
+	torsionPubKey, _ = hex.DecodeString("26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc05")
+	t.Logf("testing: %v", GetTorV3Hostname(torsionPubKey))
+	if IsValidHostname(GetTorV3Hostname(torsionPubKey)) == true {
+		t.Fatalf("torsion onion should not validate as a valid hostname")
+	}
+
+	torsionPubKey, _ = hex.DecodeString("c9fff3af0471c28e33e98c2043e44f779d0427b1e37c521a6bddc011ed1869af")
+	t.Logf("testing: %v", GetTorV3Hostname(torsionPubKey))
+	if IsValidHostname(GetTorV3Hostname(torsionPubKey)) == true {
+		t.Fatalf("torsion onion should not validate as a valid hostname")
+	}
+
+	torsionPubKey, _ = hex.DecodeString("f43e3a046db8749164c6e69b193f1e942c7452e7d888736f40b98093d814d5e7")
+	t.Logf("testing: %v", GetTorV3Hostname(torsionPubKey))
+	if IsValidHostname(GetTorV3Hostname(torsionPubKey)) == true {
+		t.Fatalf("torsion onion should not should validate as a valid hostname")
+	}
+
+	torsionPubKey, _ = hex.DecodeString("300ef2e64e588e1df55b48e4da0416ffb64cc85d5b00af6463d5cc6c2b1c185e")
+	t.Logf("testing: %v", GetTorV3Hostname(torsionPubKey))
+	if IsValidHostname(GetTorV3Hostname(torsionPubKey)) == true {
+		t.Fatalf("torsion onion should not validate as a valid hostname")
+	}
+
+	// this should pass
+	// (also from https://lists.torproject.org/pipermail/tor-dev/2017-April/012230.html)
+	validPubKey, _ := hex.DecodeString("4ba2e44760dff4c559ef3c38768c1c14a8a54740c782c8d70803e9d6e3ad8794")
+	t.Logf("testing: %v", GetTorV3Hostname(validPubKey))
+	if IsValidHostname(GetTorV3Hostname(validPubKey)) == false {
+		t.Fatalf("valid onion should validate as a valid hostname")
+	}
+
+	// Finally test a completely invalid key...
+	badPubKey, _ := hex.DecodeString("e19c65de75c68cf3b7643ea732ba9eb1a3d20d6d57ba223c2ece1df66feb5af0")
+	t.Logf("testing: %v", GetTorV3Hostname(badPubKey))
+	if IsValidHostname(GetTorV3Hostname(badPubKey)) == true {
+		t.Fatalf("invalid ed25519 point should not validate as a valid hostname")
+	}
+}
+
 func TestGenerateTorrc(t *testing.T) {
 	path := "./torrc.test"
 	password := "examplehashedpassword"