diff --git a/sign/bls/bls_test.go b/sign/bls/bls_test.go
index 0f7f3cfa9..926542ea2 100644
--- a/sign/bls/bls_test.go
+++ b/sign/bls/bls_test.go
@@ -12,6 +12,19 @@ import (
 
 func TestBLS(t *testing.T) {
 	msg := []byte("Hello Boneh-Lynn-Shacham")
+	BLSRoutine(t, msg)
+}
+
+func FuzzBLS(f *testing.F) {
+	f.Fuzz(func(t *testing.T, msg []byte) {
+		if len(msg) < 1 || len(msg) > 1000 {
+			t.Skip("msg must have byte length between 1 and 1000")
+		}
+		BLSRoutine(t, msg)
+	})
+}
+
+func BLSRoutine(t *testing.T, msg []byte) {
 	suite := bn256.NewSuite()
 	private, public := NewKeyPair(suite, random.New())
 	sig, err := Sign(suite, private, msg)
diff --git a/sign/cosi/cosi_test.go b/sign/cosi/cosi_test.go
index 437e11e98..0bc4c2bc0 100644
--- a/sign/cosi/cosi_test.go
+++ b/sign/cosi/cosi_test.go
@@ -28,15 +28,31 @@ func (m *cosiSuite) RandomStream() cipher.Stream { return m.r }
 var testSuite = &cosiSuite{edwards25519.NewBlakeSHA256Ed25519(), blake2xb.New(nil)}
 
 func TestCoSi(t *testing.T) {
-	testCoSi(t, 2, 0)
-	testCoSi(t, 5, 0)
-	testCoSi(t, 5, 2)
-	testCoSi(t, 5, 4)
+	message := []byte("Hello World Cosi")
+	testCoSi(t, 2, 0, message)
+	testCoSi(t, 2, 0, message)
+	testCoSi(t, 5, 0, message)
+	testCoSi(t, 5, 2, message)
+	testCoSi(t, 5, 4, message)
 }
 
-func testCoSi(t *testing.T, n, f int) {
-	message := []byte("Hello World Cosi")
+func FuzzCoSi(f *testing.F) {
+	f.Fuzz(func(t *testing.T, n, f int, msg []byte) {
+		if (len(msg) < 1) || (len(msg) > 1000) {
+			t.Skip("msg must have byte length between 1 and 1000")
+		}
+		if n < 1 || n > 100 {
+			t.Skip("n must be between 1 and 100")
+		}
+		if f < 0 || f >= n {
+			t.Skip("f must be between 0 and n-1")
+		}
+
+		testCoSi(t, n, f, msg)
+	})
+}
 
+func testCoSi(t *testing.T, n, f int, message []byte) {
 	// Generate key pairs
 	var kps []*key.Pair
 	var privates []kyber.Scalar
diff --git a/sign/schnorr/schnorr_test.go b/sign/schnorr/schnorr_test.go
index e669c2ce1..7a0987288 100644
--- a/sign/schnorr/schnorr_test.go
+++ b/sign/schnorr/schnorr_test.go
@@ -7,6 +7,7 @@ import (
 	"testing/quick"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"go.dedis.ch/kyber/v3/group/edwards25519"
 	"go.dedis.ch/kyber/v3/sign/eddsa"
 	"go.dedis.ch/kyber/v3/util/key"
@@ -125,3 +126,19 @@ func TestSchnorrMalleability(t *testing.T) {
 	err = Verify(suite, kp.Public, msg, s)
 	assert.Error(t, err, "schnorr signature malleable")
 }
+
+func FuzzSchnorr(f *testing.F) {
+	f.Fuzz(func(t *testing.T, msg []byte) {
+		if (len(msg) < 1) || (len(msg) > 1000) {
+			t.Skip("msg must have byte length between 1 and 1000")
+		}
+		suite := edwards25519.NewBlakeSHA256Ed25519()
+		kp := key.NewKeyPair(suite)
+
+		s, err := Sign(suite, kp.Private, msg)
+		require.NoError(t, err, "Couldn't sign msg: %s: %v", msg, err)
+
+		err = Verify(suite, kp.Public, msg, s)
+		require.NoError(t, err, "Couldn't verify signature: \n%+v\nfor msg:'%s'. Error:\n%v", s, msg, err)
+	})
+}
diff --git a/sign/tbls/tbls_test.go b/sign/tbls/tbls_test.go
index 5254bb7f6..c1fdb360a 100644
--- a/sign/tbls/tbls_test.go
+++ b/sign/tbls/tbls_test.go
@@ -10,22 +10,39 @@ import (
 )
 
 func TestTBLS(test *testing.T) {
-	var err error
-	msg := []byte("Hello threshold Boneh-Lynn-Shacham")
+	BLSRoutine(test, []byte("Hello threshold Boneh-Lynn-Shacham"), 10)
+}
+
+func FuzzBLS(f *testing.F) {
+	f.Fuzz(func(t *testing.T, msg []byte, n int) {
+		if (n < 1) || (n > 100) {
+			t.Skip("n must be between 1 and 100")
+		}
+		if (len(msg) < 1) || (len(msg) > 1000) {
+			t.Skip("msg must have byte length between 1 and 1000")
+		}
+		BLSRoutine(t, msg, n)
+	})
+}
+
+func BLSRoutine(test *testing.T, msg []byte, n int) {
 	suite := bn256.NewSuite()
-	n := 10
-	t := n/2 + 1
+	th := n/2 + 1
+
 	secret := suite.G1().Scalar().Pick(suite.RandomStream())
-	priPoly := share.NewPriPoly(suite.G2(), t, secret, suite.RandomStream())
+	priPoly := share.NewPriPoly(suite.G2(), th, secret, suite.RandomStream())
 	pubPoly := priPoly.Commit(suite.G2().Point().Base())
 	sigShares := make([][]byte, 0)
+
 	for _, x := range priPoly.Shares(n) {
 		sig, err := Sign(suite, x, msg)
 		require.Nil(test, err)
 		sigShares = append(sigShares, sig)
 	}
-	sig, err := Recover(suite, pubPoly, msg, sigShares, t, n)
+
+	sig, err := Recover(suite, pubPoly, msg, sigShares, th, n)
 	require.Nil(test, err)
+
 	err = bls.Verify(suite, pubPoly.Commit(), msg, sig)
 	require.Nil(test, err)
 }