diff --git a/signer/config.go b/signer/config.go
index 9962856e..7db96ff1 100644
--- a/signer/config.go
+++ b/signer/config.go
@@ -349,7 +349,7 @@ func ChainNodesFromFlag(nodes []string) (ChainNodes, error) {
 
 func PubKey(bech32BasePrefix string, pubKey crypto.PubKey) (string, error) {
 	if bech32BasePrefix != "" {
-		pubkey, err := cryptocodec.FromTmPubKeyInterface(pubKey)
+		pubkey, err := cryptocodec.FromCmtPubKeyInterface(pubKey)
 		if err != nil {
 			return "", err
 		}
@@ -366,7 +366,7 @@ func PubKey(bech32BasePrefix string, pubKey crypto.PubKey) (string, error) {
 	var pk *cryptotypes.PubKey
 	registry.RegisterInterface("cosmos.crypto.PubKey", pk)
 	registry.RegisterImplementations(pk, &ed25519.PubKey{})
-	sdkPK, err := cryptocodec.FromTmPubKeyInterface(pubKey)
+	sdkPK, err := cryptocodec.FromCmtPubKeyInterface(pubKey)
 	if err != nil {
 		return "", err
 	}
diff --git a/signer/threshold_signer_bls.go b/signer/threshold_signer_bls.go
new file mode 100644
index 00000000..12a8b567
--- /dev/null
+++ b/signer/threshold_signer_bls.go
@@ -0,0 +1,104 @@
+package signer
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+
+	"gitlab.com/unit410/edwards25519"
+	tsed25519 "gitlab.com/unit410/threshold-ed25519/pkg"
+)
+
+var _ ThresholdSigner = &ThresholdSignerSoftBLS{}
+
+type ThresholdSignerSoftBLS struct {
+	privateKeyShard []byte
+	pubKey          []byte
+	threshold       uint8
+	total           uint8
+}
+
+func NewThresholdSignerSoftBLS(config *RuntimeConfig, id int, chainID string) (*ThresholdSignerSoftBLS, error) {
+	keyFile, err := config.KeyFileExistsCosigner(chainID)
+	if err != nil {
+		return nil, err
+	}
+
+	key, err := LoadCosignerEd25519Key(keyFile)
+	if err != nil {
+		return nil, fmt.Errorf("error reading cosigner key: %s", err)
+	}
+
+	if key.ID != id {
+		return nil, fmt.Errorf("key shard ID (%d) in (%s) does not match cosigner ID (%d)", key.ID, keyFile, id)
+	}
+
+	s := ThresholdSignerSoftBLS{
+		privateKeyShard: key.PrivateShard,
+		pubKey:          key.PubKey.Bytes(),
+		threshold:       uint8(config.Config.ThresholdModeConfig.Threshold),
+		total:           uint8(len(config.Config.ThresholdModeConfig.Cosigners)),
+	}
+
+	return &s, nil
+}
+
+func (s *ThresholdSignerSoftBLS) PubKey() []byte {
+	return s.pubKey
+}
+
+func (s *ThresholdSignerSoftBLS) Sign(nonces []Nonce, payload []byte) ([]byte, error) {
+	nonceShare, noncePub, err := s.sumNonces(nonces)
+	if err != nil {
+		return nil, fmt.Errorf("failed to combine nonces: %w", err)
+	}
+
+	sig := tsed25519.SignWithShare(
+		payload, s.privateKeyShard, nonceShare, s.pubKey, noncePub)
+	return append(noncePub, sig...), nil
+}
+
+func (s *ThresholdSignerSoftBLS) sumNonces(nonces []Nonce) (tsed25519.Scalar, tsed25519.Element, error) {
+	shareParts := make([]tsed25519.Scalar, len(nonces))
+	publicKeys := make([]tsed25519.Element, len(nonces))
+
+	for i, n := range nonces {
+		shareParts[i] = n.Share
+		publicKeys[i] = n.PubKey
+	}
+
+	nonceShare := tsed25519.AddScalars(shareParts)
+	noncePub := tsed25519.AddElements(publicKeys)
+
+	// check bounds for ephemeral share to avoid passing out of bounds valids to SignWithShare
+	if len(nonceShare) != 32 {
+		return nil, nil, errors.New("ephemeral share is out of bounds")
+	}
+
+	var scalarBytes [32]byte
+	copy(scalarBytes[:], nonceShare)
+	if !edwards25519.ScMinimal(&scalarBytes) {
+		return nil, nil, errors.New("ephemeral share is out of bounds")
+	}
+
+	return nonceShare, noncePub, nil
+}
+
+func (s *ThresholdSignerSoftBLS) CombineSignatures(signatures []PartialSignature) ([]byte, error) {
+	sigIds := make([]int, len(signatures))
+	shareSigs := make([][]byte, len(signatures))
+	var ephPub []byte
+
+	for i, sig := range signatures {
+		sigIds[i] = sig.ID
+		if i == 0 {
+			ephPub = sig.Signature[:32]
+		} else if !bytes.Equal(sig.Signature[:32], ephPub) {
+			return nil, fmt.Errorf("ephemeral public keys do not match")
+		}
+		shareSigs[i] = sig.Signature[32:]
+	}
+	combinedSig := tsed25519.CombineShares(s.total, sigIds, shareSigs)
+
+	return append(ephPub, combinedSig...), nil
+}