diff --git a/internal/core/execute/v2/block/sig_user.go b/internal/core/execute/v2/block/sig_user.go
index 0cd68a756..78c741643 100644
--- a/internal/core/execute/v2/block/sig_user.go
+++ b/internal/core/execute/v2/block/sig_user.go
@@ -33,15 +33,10 @@ func init() {
 		protocol.SignatureTypeETH,
 	)
 
-	// RSA signatures (enabled with Vandenberg)
+	// Vandenberg: RSA and ECDSA signatures
 	registerConditionalExec[UserSignature](&signatureExecutors,
 		func(ctx *SignatureContext) bool { return ctx.GetActiveGlobals().ExecutorVersion.V2VandenbergEnabled() },
 		protocol.SignatureTypeRsaSha256,
-	)
-
-	// PKI signatures (enabled with Vandenberg)
-	registerConditionalExec[UserSignature](&signatureExecutors,
-		func(ctx *SignatureContext) bool { return ctx.GetActiveGlobals().ExecutorVersion.V2VandenbergEnabled() },
 		protocol.SignatureTypeEcdsaSha256,
 	)
 }
@@ -138,6 +133,14 @@ func (x UserSignature) check(batch *database.Batch, ctx *userSigContext) error {
 		return errors.UnknownError.Wrap(err)
 	}
 
+	// A lite identity may not require additional authorities
+	if ctx.GetActiveGlobals().ExecutorVersion.V2VandenbergEnabled() &&
+		ctx.signer.Type() == protocol.AccountTypeLiteIdentity &&
+		len(ctx.transaction.Header.Authorities) > 0 &&
+		ctx.isInitiator {
+		return errors.BadRequest.WithFormat("a transaction initiated by a lite identity cannot require additional authorities")
+	}
+
 	return nil
 }
 
@@ -437,25 +440,23 @@ func (UserSignature) process(batch *database.Batch, ctx *userSigContext) error {
 // sendSignatureRequests sends signature requests so that the transaction
 // will appear on the appropriate pending lists.
 func (UserSignature) sendSignatureRequests(batch *database.Batch, ctx *userSigContext) error {
-	// If the signer is a lite identity, do not send a signature request
-	if _, ok := ctx.signer.(*protocol.LiteIdentity); ok &&
-		ctx.GetActiveGlobals().ExecutorVersion.V2VandenbergEnabled() {
-		return nil
-	}
-
 	// If this is the initiator signature
 	if !ctx.isInitiator {
 		return nil
 	}
 
-	// Send a notice to the principal
-	msg := new(messaging.SignatureRequest)
-	msg.Authority = ctx.transaction.Header.Principal
-	msg.Cause = ctx.message.ID()
-	msg.TxID = ctx.transaction.ID()
-	err := ctx.didProduce(batch, msg.Authority, msg)
-	if err != nil {
-		return errors.UnknownError.Wrap(err)
+	// Send a notice to the principal, unless principal is a lite identity
+	_, err := protocol.ParseLiteAddress(ctx.transaction.Header.Principal)
+	isLite := err == nil && ctx.GetActiveGlobals().ExecutorVersion.V2VandenbergEnabled()
+	if !isLite {
+		msg := new(messaging.SignatureRequest)
+		msg.Authority = ctx.transaction.Header.Principal
+		msg.Cause = ctx.message.ID()
+		msg.TxID = ctx.transaction.ID()
+		err := ctx.didProduce(batch, msg.Authority, msg)
+		if err != nil {
+			return errors.UnknownError.Wrap(err)
+		}
 	}
 
 	// If transaction requests additional authorities, send out signature requests
diff --git a/test/e2e/sig_general_test.go b/test/e2e/sig_general_test.go
index 29c7be34f..33ea6b302 100644
--- a/test/e2e/sig_general_test.go
+++ b/test/e2e/sig_general_test.go
@@ -463,6 +463,43 @@ func TestSignatureErrors(t *testing.T) {
 	require.ErrorContains(t, err, "insufficient credits: have 0.00, want 0.01")
 }
 
+// Verifies that ADI accounts do produce signature requests.
+func TestAdiAccountSignatureRequests(t *testing.T) {
+	alice := build.
+		Identity("alice").Create("book").
+		Tokens("tokens").Create("ACME").Add(1e9).Identity().
+		Book("book").Page(1).Create().AddCredits(1e9).Book().Identity()
+	aliceKey := alice.Book("book").Page(1).
+		GenerateKey(SignatureTypeED25519)
+
+	// Initialize
+	sim := NewSim(t,
+		simulator.SimpleNetwork(t.Name(), 1, 1),
+		simulator.Genesis(GenesisTime).With(alice),
+	)
+
+	// Execute a transaction
+	st := sim.BuildAndSubmitSuccessfully(
+		build.Transaction().For(alice, "tokens").
+			AddCredits().Spend(10).To(alice, "book", "1").WithOracle(InitialAcmeOracle).
+			SignWith(alice, "book", "1").Version(1).Timestamp(1).PrivateKey(aliceKey))
+
+	sim.StepUntil(
+		Txn(st[0].TxID).Completes())
+
+	// Verify that the signature did not produce any signature requests
+	r := sim.QuerySignature(st[1].TxID, nil)
+	var ok bool
+	for _, r := range r.Produced.Records {
+		r := sim.QueryMessage(r.Value, nil)
+		_, x := r.Message.(*messaging.SignatureRequest)
+		if x {
+			ok = true
+		}
+	}
+	require.True(t, ok, "A signature request is produced")
+}
+
 // Verifies that lite accounts do not produce signature requests.
 func TestLiteAccountSignatureRequests(t *testing.T) {
 	lite := build.LiteIdentity().Generate(t).AddCredits(1000).
@@ -491,3 +528,24 @@ func TestLiteAccountSignatureRequests(t *testing.T) {
 		require.False(t, ok, "A signature request is not produced")
 	}
 }
+
+func TestLiteAdditionalAuthorities(t *testing.T) {
+	lite := build.LiteIdentity().Generate(t).AddCredits(1000).
+		Tokens("ACME").Create().Add(1000).Identity()
+
+	// Initialize
+	sim := NewSim(t,
+		simulator.SimpleNetwork(t.Name(), 1, 1),
+		simulator.Genesis(GenesisTime).With(lite),
+	)
+
+	// Execute a transaction with additional authorities
+	st := sim.BuildAndSubmit(
+		build.Transaction().For(lite, "ACME").
+			AdditionalAuthority("alice.acme/book/1").
+			AddCredits().Spend(10).To(lite).WithOracle(InitialAcmeOracle).
+			SignWith(lite).Version(1).Timestamp(1).PrivateKey(lite.Key))
+
+	require.Error(t, st[1].AsError())
+	require.ErrorContains(t, st[1].Error, "a transaction initiated by a lite identity cannot require additional authorities")
+}