diff --git a/nano/keys.go b/nano/keys.go
new file mode 100644
index 000000000..7b76fa87f
--- /dev/null
+++ b/nano/keys.go
@@ -0,0 +1,150 @@
+package nano
+
+import (
+	"bytes"
+	"encoding/hex"
+
+	crypto "github.com/tendermint/go-crypto"
+)
+
+// // Implements PrivKey, calling the ledger nano
+// type PrivKeyLedger struct{}
+
+// var _ PrivKeyInner = PrivKeyLedger{}
+
+// func (privKey PrivKeyLedger) AssertIsPrivKeyInner() {}
+
+// func (privKey PrivKeyLedger) Bytes() []byte {
+// 	return wire.BinaryBytes(PrivKey{privKey})
+// }
+
+// func (privKey PrivKeyLedger) Sign(msg []byte) Signature {
+// 	privKeyBytes := [64]byte(privKey)
+// 	signatureBytes := ed25519.Sign(&privKeyBytes, msg)
+// 	return SignatureEd25519(*signatureBytes).Wrap()
+// }
+
+// func (privKey PrivKeyLedger) PubKey() PubKey {
+// 	privKeyBytes := [64]byte(privKey)
+// 	pubBytes := *ed25519.MakePublicKey(&privKeyBytes)
+// 	return PubKeyEd25519(pubBytes).Wrap()
+// }
+
+// func (privKey PrivKeyLedger) Equals(other PrivKey) bool {
+// 	if otherEd, ok := other.Unwrap().(PrivKeyLedger); ok {
+// 		return bytes.Equal(privKey[:], otherEd[:])
+// 	} else {
+// 		return false
+// 	}
+// }
+
+// MockPrivKeyLedger behaves as the ledger, but stores a pre-packaged call-response
+// for use in test cases
+type MockPrivKeyLedger struct {
+	Msg []byte
+	Pub [KeyLength]byte
+	Sig [SigLength]byte
+}
+
+// NewMockKey returns
+func NewMockKey(msg, pubkey, sig string) (pk MockPrivKeyLedger) {
+	var err error
+	pk.Msg, err = hex.DecodeString(msg)
+	if err != nil {
+		panic(err)
+	}
+
+	bpk, err := hex.DecodeString(pubkey)
+	if err != nil {
+		panic(err)
+	}
+	bsig, err := hex.DecodeString(sig)
+	if err != nil {
+		panic(err)
+	}
+
+	copy(pk.Pub[:], bpk)
+	copy(pk.Sig[:], bsig)
+	return pk
+}
+
+var _ crypto.PrivKeyInner = MockPrivKeyLedger{}
+
+// AssertIsPrivKeyInner fulfils PrivKey Interface
+func (pk MockPrivKeyLedger) AssertIsPrivKeyInner() {}
+
+// Bytes fulfils PrivKey Interface - not supported
+func (pk MockPrivKeyLedger) Bytes() []byte {
+	return nil
+}
+
+// Sign returns a real SignatureLedger, if the msg matches what we expect
+func (pk MockPrivKeyLedger) Sign(msg []byte) crypto.Signature {
+	if !bytes.Equal(pk.Msg, msg) {
+		panic("Mock key is for different msg")
+	}
+	return crypto.SignatureEd25519(pk.Sig).Wrap()
+}
+
+// PubKey returns a real PubKeyLedger, that will verify this signature
+func (pk MockPrivKeyLedger) PubKey() crypto.PubKey {
+	return PubKeyLedger{crypto.PubKeyEd25519(pk.Pub)}.Wrap()
+}
+
+// Equals compares that two Mocks have the same data
+func (pk MockPrivKeyLedger) Equals(other crypto.PrivKey) bool {
+	if mock, ok := other.Unwrap().(MockPrivKeyLedger); ok {
+		return bytes.Equal(mock.Pub[:], pk.Pub[:]) &&
+			bytes.Equal(mock.Sig[:], pk.Sig[:]) &&
+			bytes.Equal(mock.Msg, pk.Msg)
+	}
+	return false
+}
+
+////////////////////////////////////////////
+// pubkey
+
+// PubKeyLedger works like a normal Ed25519 except a hash before the verify bytes
+type PubKeyLedger struct {
+	crypto.PubKeyEd25519
+}
+
+// VerifyBytes uses the normal Ed25519 algorithm but a sha512 hash beforehand
+func (pk PubKeyLedger) VerifyBytes(msg []byte, sig crypto.Signature) bool {
+	hmsg := hashMsg(msg)
+	return pk.PubKeyEd25519.VerifyBytes(hmsg, sig)
+}
+
+// Equals implements PubKey interface
+func (pk PubKeyLedger) Equals(other crypto.PubKey) bool {
+	if ledger, ok := other.Unwrap().(PubKeyLedger); ok {
+		return bytes.Equal(pk.PubKeyEd25519[:], ledger.PubKeyEd25519[:])
+	}
+	return false
+}
+
+/*** registration with go-data ***/
+
+func init() {
+	crypto.PrivKeyMapper.
+		// RegisterImplementation(PrivKeyLedger{}, "ledger", 0x10).
+		RegisterImplementation(MockPrivKeyLedger{}, "mock-ledger", 0x11)
+
+	crypto.PubKeyMapper.
+		RegisterImplementation(PubKeyLedger{}, "ledger", 0x10)
+}
+
+// // Wrap fulfils interface for PrivKey struct
+// func (hi PrivKeyLedger) Wrap() crypto.PrivKey {
+// 	return PrivKey{hi}
+// }
+
+// Wrap fulfils interface for PrivKey struct
+func (pk MockPrivKeyLedger) Wrap() crypto.PrivKey {
+	return crypto.PrivKey{pk}
+}
+
+// Wrap fulfils interface for PubKey struct
+func (pk PubKeyLedger) Wrap() crypto.PubKey {
+	return crypto.PubKey{pk}
+}