diff --git a/acme/api/account.go b/acme/api/account.go
index bf8fdfe5..fa5597e0 100644
--- a/acme/api/account.go
+++ b/acme/api/account.go
@@ -265,7 +265,6 @@ func (h *Handler) validateExternalAccountBinding(ctx context.Context, nar *NewAc
 		return nil, acme.WrapErrorISE(err, "error parsing externalAccountBinding jws")
 	}
 
-	// TODO: verify supported algorithms against the incoming alg (and corresponding settings)?
 	// TODO: implement strategy pattern to allow for different ways of verification (i.e. webhook call) based on configuration
 
 	keyID := eabJWS.Signatures[0].Protected.KeyID
diff --git a/authority/admin/api/acme.go b/authority/admin/api/acme.go
index 36fc10fe..7772e435 100644
--- a/authority/admin/api/acme.go
+++ b/authority/admin/api/acme.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/smallstep/certificates/api"
 	"github.com/smallstep/certificates/authority/admin"
+	"go.step.sm/linkedca"
 )
 
 // CreateExternalAccountKeyRequest is the type for POST /admin/acme/eab requests
@@ -13,29 +14,35 @@ type CreateExternalAccountKeyRequest struct {
 	Name            string `json:"name"`
 }
 
-// CreateExternalAccountKeyResponse is the type for POST /admin/acme/eab responses
-type CreateExternalAccountKeyResponse struct {
-	ProvisionerName string `json:"provisioner"`
-	KeyID           string `json:"keyID"`
-	Name            string `json:"name"`
-	Key             []byte `json:"key"`
+// Validate validates a new-admin request body.
+func (r *CreateExternalAccountKeyRequest) Validate() error {
+	if r.ProvisionerName == "" {
+		return admin.NewError(admin.ErrorBadRequestType, "provisioner name cannot be empty")
+	}
+	if r.Name == "" {
+		return admin.NewError(admin.ErrorBadRequestType, "name / reference cannot be empty")
+	}
+	return nil
 }
 
 // GetExternalAccountKeysResponse is the type for GET /admin/acme/eab responses
 type GetExternalAccountKeysResponse struct {
-	EAKs       []*CreateExternalAccountKeyResponse `json:"eaks"`
-	NextCursor string                              `json:"nextCursor"`
+	EAKs       []*linkedca.EABKey `json:"eaks"`
+	NextCursor string             `json:"nextCursor"`
 }
 
 // CreateExternalAccountKey creates a new External Account Binding key
 func (h *Handler) CreateExternalAccountKey(w http.ResponseWriter, r *http.Request) {
 	var body CreateExternalAccountKeyRequest
 	if err := api.ReadJSON(r.Body, &body); err != nil { // TODO: rewrite into protobuf json (likely)
-		api.WriteError(w, err)
+		api.WriteError(w, admin.WrapError(admin.ErrorBadRequestType, err, "error reading request body"))
 		return
 	}
 
-	// TODO: Validate input
+	if err := body.Validate(); err != nil {
+		api.WriteError(w, err)
+		return
+	}
 
 	eak, err := h.acmeDB.CreateExternalAccountKey(r.Context(), body.ProvisionerName, body.Name)
 	if err != nil {
@@ -43,14 +50,14 @@ func (h *Handler) CreateExternalAccountKey(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	eakResponse := CreateExternalAccountKeyResponse{
+	response := &linkedca.EABKey{
+		EabKid:          eak.ID,
+		EabHmacKey:      eak.KeyBytes,
 		ProvisionerName: eak.ProvisionerName,
-		KeyID:           eak.ID,
 		Name:            eak.Name,
-		Key:             eak.KeyBytes,
 	}
 
-	api.JSONStatus(w, eakResponse, http.StatusCreated) // TODO: rewrite into protobuf json (likely)
+	api.ProtoJSONStatus(w, response, http.StatusCreated)
 }
 
 // GetExternalAccountKeys returns a segment of ACME EAB Keys.
diff --git a/ca/adminClient.go b/ca/adminClient.go
index 7f24efa9..06462051 100644
--- a/ca/adminClient.go
+++ b/ca/adminClient.go
@@ -12,7 +12,6 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
-	"github.com/smallstep/certificates/api"
 	"github.com/smallstep/certificates/authority/admin"
 	adminAPI "github.com/smallstep/certificates/authority/admin/api"
 	"github.com/smallstep/certificates/authority/provisioner"
@@ -600,7 +599,7 @@ retry:
 }
 
 // CreateExternalAccountKey performs the POST /admin/acme/eab request to the CA.
-func (c *AdminClient) CreateExternalAccountKey(eakRequest *adminAPI.CreateExternalAccountKeyRequest) (*adminAPI.CreateExternalAccountKeyResponse, error) {
+func (c *AdminClient) CreateExternalAccountKey(eakRequest *adminAPI.CreateExternalAccountKeyRequest) (*linkedca.EABKey, error) {
 	var retried bool
 	body, err := json.Marshal(eakRequest)
 	if err != nil {
@@ -628,18 +627,18 @@ retry:
 		}
 		return nil, readAdminError(resp.Body)
 	}
-	var eakResp = new(adminAPI.CreateExternalAccountKeyResponse)
-	if err := api.ReadJSON(resp.Body, &eakResp); err != nil {
+	var eabKey = new(linkedca.EABKey)
+	if err := readProtoJSON(resp.Body, eabKey); err != nil {
 		return nil, errors.Wrapf(err, "error reading %s", u)
 	}
-	return eakResp, nil
+	return eabKey, nil
 }
 
 // GetExternalAccountKeys returns all ACME EAB Keys from the GET /admin/acme/eab request to the CA.
-func (c *AdminClient) GetExternalAccountKeys(opts ...AdminOption) ([]*adminAPI.CreateExternalAccountKeyResponse, error) {
+func (c *AdminClient) GetExternalAccountKeys(opts ...AdminOption) ([]*linkedca.EABKey, error) {
 	var (
 		cursor = ""
-		eaks   = []*adminAPI.CreateExternalAccountKeyResponse{}
+		eaks   = []*linkedca.EABKey{}
 	)
 	for {
 		resp, err := c.GetExternalAccountKeysPaginate(WithAdminCursor(cursor), WithAdminLimit(100))