--- a/src/event/quic/ngx_event_quic_protection.h
+++ b/src/event/quic/ngx_event_quic_protection.h
@@ -16,8 +16,46 @@
 
 #define NGX_QUIC_ENCRYPTION_LAST  ((ssl_encryption_application) + 1)
 
+/* RFC 5116, 5.1 and RFC 8439, 2.3 for all supported ciphers */
+#define NGX_QUIC_IV_LEN               12
 
-ngx_quic_keys_t *ngx_quic_keys_new(ngx_pool_t *pool);
+/* largest hash used in TLS is SHA-384 */
+#define NGX_QUIC_MAX_MD_SIZE          48
+
+
+typedef struct {
+    size_t                    len;
+    u_char                    data[NGX_QUIC_MAX_MD_SIZE];
+} ngx_quic_md_t;
+
+
+typedef struct {
+    size_t                    len;
+    u_char                    data[NGX_QUIC_IV_LEN];
+} ngx_quic_iv_t;
+
+
+typedef struct {
+    ngx_quic_md_t             secret;
+    ngx_quic_md_t             key;
+    ngx_quic_iv_t             iv;
+    ngx_quic_md_t             hp;
+} ngx_quic_secret_t;
+
+
+typedef struct {
+    ngx_quic_secret_t         client;
+    ngx_quic_secret_t         server;
+} ngx_quic_secrets_t;
+
+
+struct ngx_quic_keys_s {
+    ngx_quic_secrets_t        secrets[NGX_QUIC_ENCRYPTION_LAST];
+    ngx_quic_secrets_t        next_key;
+    ngx_uint_t                cipher;
+};
+
+
 ngx_int_t ngx_quic_keys_set_initial_secret(ngx_quic_keys_t *keys,
     ngx_str_t *secret, ngx_log_t *log);
 ngx_int_t ngx_quic_keys_set_encryption_secret(ngx_log_t *log,