diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-aes.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-aes.h
index 8b1904ae05..e9c74ff8f1 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-aes.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-aes.h
@@ -145,7 +145,8 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_trezorcrypto_AES_update_obj, mod_trezorcryp
 
 STATIC mp_obj_t mod_trezorcrypto_AES___del__(mp_obj_t self) {
     mp_obj_AES_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(aes_encrypt_ctx));
+    explicit_bzero(&(o->ctx), sizeof(aes_encrypt_ctx));
+    explicit_bzero(o->iv, AES_BLOCK_SIZE);
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_AES___del___obj, mod_trezorcrypto_AES___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h
index d32883c82d..7b327a8031 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h
@@ -93,17 +93,17 @@ STATIC mp_obj_t mod_trezorcrypto_HDNode_make_new(const mp_obj_type_t *type, size
     if (NULL != chain_code.buf && 32 == chain_code.len) {
         memcpy(o->hdnode.chain_code, chain_code.buf, 32);
     } else {
-        memset(o->hdnode.chain_code, 0, 32);
+        explicit_bzero(o->hdnode.chain_code, 32);
     }
     if (NULL != private_key.buf && 32 == private_key.len) {
         memcpy(o->hdnode.private_key, private_key.buf, 32);
     } else {
-        memset(o->hdnode.private_key, 0, 32);
+        explicit_bzero(o->hdnode.private_key, 32);
     }
     if (NULL != public_key.buf && 33 == public_key.len) {
         memcpy(o->hdnode.public_key, public_key.buf, 33);
     } else {
-        memset(o->hdnode.public_key, 0, 33);
+        explicit_bzero(o->hdnode.public_key, 33);
     }
     o->hdnode.curve = curve;
 
@@ -120,7 +120,7 @@ STATIC mp_obj_t mod_trezorcrypto_HDNode_derive(mp_obj_t self, mp_obj_t index) {
     uint32_t fp = hdnode_fingerprint(&o->hdnode);
 
     if (!hdnode_private_ckd(&o->hdnode, i)) {
-        memset(&o->hdnode, 0, sizeof(o->hdnode));
+        explicit_bzero(&o->hdnode, sizeof(o->hdnode));
         mp_raise_ValueError("Failed to derive");
     }
     o->fingerprint = fp;
@@ -157,7 +157,7 @@ STATIC mp_obj_t mod_trezorcrypto_HDNode_derive_path(mp_obj_t self, mp_obj_t path
     if (!hdnode_private_ckd_cached(&o->hdnode, pints, plen, &o->fingerprint)) {
         // derivation failed, reset the state and raise
         o->fingerprint = 0;
-        memset(&o->hdnode, 0, sizeof(o->hdnode));
+        explicit_bzero(&o->hdnode, sizeof(o->hdnode));
         mp_raise_ValueError("Failed to derive path");
     }
 
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake256.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake256.h
index dc1ae15e5e..e60668b05c 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake256.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake256.h
@@ -68,7 +68,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Blake256_digest_obj, mod_trezo
 
 STATIC mp_obj_t mod_trezorcrypto_Blake256___del__(mp_obj_t self) {
     mp_obj_Blake256_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(BLAKE256_CTX));
+    explicit_bzero(&(o->ctx), sizeof(BLAKE256_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Blake256___del___obj, mod_trezorcrypto_Blake256___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2b.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2b.h
index b3b298aef3..fd02af69d7 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2b.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2b.h
@@ -75,7 +75,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Blake2b_digest_obj, mod_trezor
 
 STATIC mp_obj_t mod_trezorcrypto_Blake2b___del__(mp_obj_t self) {
     mp_obj_Blake2b_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(BLAKE2B_CTX));
+    explicit_bzero(&(o->ctx), sizeof(BLAKE2B_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Blake2b___del___obj, mod_trezorcrypto_Blake2b___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2s.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2s.h
index 5806e38c99..2c277c716d 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2s.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-blake2s.h
@@ -75,7 +75,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Blake2s_digest_obj, mod_trezor
 
 STATIC mp_obj_t mod_trezorcrypto_Blake2s___del__(mp_obj_t self) {
     mp_obj_Blake2s_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(BLAKE2S_CTX));
+    explicit_bzero(&(o->ctx), sizeof(BLAKE2S_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Blake2s___del___obj, mod_trezorcrypto_Blake2s___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-chacha20poly1305.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-chacha20poly1305.h
index 1779b0cc9d..2be22902be 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-chacha20poly1305.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-chacha20poly1305.h
@@ -105,7 +105,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_ChaCha20Poly1305_finish_obj, m
 
 STATIC mp_obj_t mod_trezorcrypto_ChaCha20Poly1305___del__(mp_obj_t self) {
     mp_obj_ChaCha20Poly1305_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(chacha20poly1305_ctx));
+    explicit_bzero(&(o->ctx), sizeof(chacha20poly1305_ctx));
     o->alen = 0;
     o->plen = 0;
     return mp_const_none;
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-pbkdf2.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-pbkdf2.h
index e626ee4854..4c551fa3db 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-pbkdf2.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-pbkdf2.h
@@ -111,8 +111,8 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Pbkdf2_key_obj, mod_trezorcryp
 
 STATIC mp_obj_t mod_trezorcrypto_Pbkdf2___del__(mp_obj_t self) {
     mp_obj_Pbkdf2_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx256), 0, sizeof(PBKDF2_HMAC_SHA256_CTX));
-    memset(&(o->ctx512), 0, sizeof(PBKDF2_HMAC_SHA512_CTX));
+    explicit_bzero(&(o->ctx256), sizeof(PBKDF2_HMAC_SHA256_CTX));
+    explicit_bzero(&(o->ctx512), sizeof(PBKDF2_HMAC_SHA512_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Pbkdf2___del___obj, mod_trezorcrypto_Pbkdf2___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-ripemd160.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-ripemd160.h
index 5dd22956aa..5b54aca730 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-ripemd160.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-ripemd160.h
@@ -68,7 +68,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Ripemd160_digest_obj, mod_trez
 
 STATIC mp_obj_t mod_trezorcrypto_Ripemd160___del__(mp_obj_t self) {
     mp_obj_Ripemd160_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(RIPEMD160_CTX));
+    explicit_bzero(&(o->ctx), sizeof(RIPEMD160_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Ripemd160___del___obj, mod_trezorcrypto_Ripemd160___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha1.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha1.h
index b6dd24614c..49f51285c8 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha1.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha1.h
@@ -68,7 +68,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha1_digest_obj, mod_trezorcry
 
 STATIC mp_obj_t mod_trezorcrypto_Sha1___del__(mp_obj_t self) {
     mp_obj_Sha1_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(SHA1_CTX));
+    explicit_bzero(&(o->ctx), sizeof(SHA1_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha1___del___obj, mod_trezorcrypto_Sha1___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha256.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha256.h
index a7bb8a86bd..da26a63a98 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha256.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha256.h
@@ -68,7 +68,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha256_digest_obj, mod_trezorc
 
 STATIC mp_obj_t mod_trezorcrypto_Sha256___del__(mp_obj_t self) {
     mp_obj_Sha256_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(SHA256_CTX));
+    explicit_bzero(&(o->ctx), sizeof(SHA256_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha256___del___obj, mod_trezorcrypto_Sha256___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-256.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-256.h
index f5815d99c6..92d92a7e29 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-256.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-256.h
@@ -72,7 +72,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_trezorcrypto_Sha3_256_digest_obj,
 
 STATIC mp_obj_t mod_trezorcrypto_Sha3_256___del__(mp_obj_t self) {
     mp_obj_Sha3_256_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(SHA3_CTX));
+    explicit_bzero(&(o->ctx), sizeof(SHA3_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha3_256___del___obj, mod_trezorcrypto_Sha3_256___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-512.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-512.h
index 5e720f591b..a0f366964e 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-512.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha3-512.h
@@ -72,7 +72,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_trezorcrypto_Sha3_512_digest_obj,
 
 STATIC mp_obj_t mod_trezorcrypto_Sha3_512___del__(mp_obj_t self) {
     mp_obj_Sha3_512_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(SHA3_CTX));
+    explicit_bzero(&(o->ctx), sizeof(SHA3_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha3_512___del___obj, mod_trezorcrypto_Sha3_512___del__);
diff --git a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha512.h b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha512.h
index 1098a4185c..27ea40cd61 100644
--- a/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha512.h
+++ b/embed/extmod/modtrezorcrypto/modtrezorcrypto-sha512.h
@@ -67,7 +67,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha512_digest_obj, mod_trezorc
 
 STATIC mp_obj_t mod_trezorcrypto_Sha512___del__(mp_obj_t self) {
     mp_obj_Sha512_t *o = MP_OBJ_TO_PTR(self);
-    memset(&(o->ctx), 0, sizeof(SHA512_CTX));
+    explicit_bzero(&(o->ctx), sizeof(SHA512_CTX));
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_Sha512___del___obj, mod_trezorcrypto_Sha512___del__);
diff --git a/vendor/trezor-crypto b/vendor/trezor-crypto
index 0d8a3beeaf..b7f73ee3ff 160000
--- a/vendor/trezor-crypto
+++ b/vendor/trezor-crypto
@@ -1 +1 @@
-Subproject commit 0d8a3beeaf22af837f558a5b5e9ae98cdd47a767
+Subproject commit b7f73ee3ff78e09c266a30dbc31407558d471615