diff --git a/crypto/der.c b/crypto/der.c
index ebbecfc..8136752 100644
--- a/crypto/der.c
+++ b/crypto/der.c
@@ -408,19 +408,6 @@
     qcrypto_der_encode_prim(ctx, tag, src, src_len);
 }
 
-void qcrypto_der_encode_octet_str_begin(QCryptoEncodeContext *ctx)
-{
-    uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV,
-                                  QCRYPTO_DER_TAG_ENC_PRIM,
-                                  QCRYPTO_DER_TYPE_TAG_OCT_STR);
-    qcrypto_der_encode_cons_begin(ctx, tag);
-}
-
-void qcrypto_der_encode_octet_str_end(QCryptoEncodeContext *ctx)
-{
-    qcrypto_der_encode_cons_end(ctx);
-}
-
 size_t qcrypto_der_encode_ctx_buffer_len(QCryptoEncodeContext *ctx)
 {
     return ctx->root.dlen;
diff --git a/crypto/der.h b/crypto/der.h
index f4ba6da..bcfa4a2 100644
--- a/crypto/der.h
+++ b/crypto/der.h
@@ -243,28 +243,6 @@
                                   const uint8_t *src, size_t src_len);
 
 /**
- * qcrypto_der_encode_octet_str_begin:
- * @ctx: the encode context.
- *
- * Start encoding a octet string, All fields between
- * qcrypto_der_encode_octet_str_begin and qcrypto_der_encode_octet_str_end
- * are encoded as an octet string. This is useful when we need to encode a
- * encoded SEQUENCE as OCTET STRING.
- */
-void qcrypto_der_encode_octet_str_begin(QCryptoEncodeContext *ctx);
-
-/**
- * qcrypto_der_encode_octet_str_end:
- * @ctx: the encode context.
- *
- * Finish encoding a octet string, All fields between
- * qcrypto_der_encode_octet_str_begin and qcrypto_der_encode_octet_str_end
- * are encoded as an octet string. This is useful when we need to encode a
- * encoded SEQUENCE as OCTET STRING.
- */
-void qcrypto_der_encode_octet_str_end(QCryptoEncodeContext *ctx);
-
-/**
  * qcrypto_der_encode_ctx_buffer_len:
  * @ctx: the encode context.
  *