diff --git a/testutil/sample/sample.go b/testutil/sample/sample.go
index f1d1e56..4adac68 100644
--- a/testutil/sample/sample.go
+++ b/testutil/sample/sample.go
@@ -114,3 +114,9 @@ func ExtendedKeyPair(cfg chaincfg.Params) (string, string) {
 	}
 	return xprivKey.String(), xpubKey.String()
 }
+
+func TrustAnchor() machinetypes.TrustAnchor {
+	return machinetypes.TrustAnchor{
+		Pubkey: PubKey,
+	}
+}
diff --git a/x/machine/keeper/msg_server_register_trust_anchor.go b/x/machine/keeper/msg_server_register_trust_anchor.go
index 39c911c..886c6b0 100644
--- a/x/machine/keeper/msg_server_register_trust_anchor.go
+++ b/x/machine/keeper/msg_server_register_trust_anchor.go
@@ -2,16 +2,28 @@ package keeper
 
 import (
 	"context"
+	"errors"
+
+	config "planetmint-go/config"
+	"planetmint-go/x/machine/types"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
-	"planetmint-go/x/machine/types"
 )
 
 func (k msgServer) RegisterTrustAnchor(goCtx context.Context, msg *types.MsgRegisterTrustAnchor) (*types.MsgRegisterTrustAnchorResponse, error) {
 	ctx := sdk.UnwrapSDKContext(goCtx)
 
-	// TODO: Handling the message
-	_ = ctx
+	isValidTrustAnchorPubkey := validateExtendedPublicKey(msg.TrustAnchor.Pubkey, config.LiquidNetParams)
+	if !isValidTrustAnchorPubkey {
+		return nil, errors.New("invalid trust anchor pubkey")
+	}
+
+	_, _, found := k.GetTrustAnchor(ctx, msg.TrustAnchor.Pubkey)
+	if found {
+		return nil, errors.New("trust anchor is already registered")
+	}
+
+	k.StoreTrustAnchor(ctx, *msg.TrustAnchor, false)
 
 	return &types.MsgRegisterTrustAnchorResponse{}, nil
 }
diff --git a/x/machine/keeper/msg_server_test.go b/x/machine/keeper/msg_server_test.go
index 39778cd..62a626f 100644
--- a/x/machine/keeper/msg_server_test.go
+++ b/x/machine/keeper/msg_server_test.go
@@ -46,3 +46,36 @@ func TestMsgServerAttestMachineInvalidLiquidKey(t *testing.T) {
 	_, err := msgServer.AttestMachine(ctx, msg)
 	assert.EqualError(t, err, "invalid liquid key")
 }
+
+func TestMsgServerRegisterTrustAnchor(t *testing.T) {
+	_, pk := sample.KeyPair()
+	ta := sample.TrustAnchor()
+	msg := types.NewMsgRegisterTrustAnchor(pk, &ta)
+	msgServer, ctx := setupMsgServer(t)
+	res, err := msgServer.RegisterTrustAnchor(ctx, msg)
+	if assert.NoError(t, err) {
+		assert.Equal(t, &types.MsgRegisterTrustAnchorResponse{}, res)
+	}
+}
+
+func TestMsgServerRegisterTrustAnchorTwice(t *testing.T) {
+	_, pk := sample.KeyPair()
+	ta := sample.TrustAnchor()
+	msg := types.NewMsgRegisterTrustAnchor(pk, &ta)
+	msgServer, ctx := setupMsgServer(t)
+	res, err := msgServer.RegisterTrustAnchor(ctx, msg)
+	if assert.NoError(t, err) {
+		assert.Equal(t, &types.MsgRegisterTrustAnchorResponse{}, res)
+	}
+	_, err = msgServer.RegisterTrustAnchor(ctx, msg)
+	assert.EqualError(t, err, "trust anchor is already registered")
+}
+
+func TestMsgServerRegisterTrustAnchorInvalidPubkey(t *testing.T) {
+	_, pk := sample.KeyPair()
+	ta := sample.TrustAnchor()
+	msg := types.NewMsgRegisterTrustAnchor(pk, &ta)
+	msgServer, ctx := setupMsgServer(t)
+	_, err := msgServer.RegisterTrustAnchor(ctx, msg)
+	assert.EqualError(t, err, "invalid trust anchor pubkey")
+}