diff --git a/crypto/base32.c b/crypto/base32.c
index 1d49a0c24..ef9b76bec 100644
--- a/crypto/base32.c
+++ b/crypto/base32.c
@@ -153,6 +153,7 @@ bool base32_8to5(const uint8_t *in, uint8_t length, uint8_t *out,
 
   if (alphabet) {
     uint8_t decoded[length];
+    memset(decoded, 0, sizeof(decoded));
 
     for (size_t i = 0; i < length; i++) {
       int ret = base32_decode_character(in[i], alphabet);
diff --git a/crypto/base58.c b/crypto/base58.c
index 71423726c..d95ac9a9d 100644
--- a/crypto/base58.c
+++ b/crypto/base58.c
@@ -190,6 +190,7 @@ int base58_encode_check(const uint8_t *data, int datalen,
     return 0;
   }
   uint8_t buf[datalen + 32];
+  memset(buf, 0, sizeof(buf));
   uint8_t *hash = buf + datalen;
   memcpy(buf, data, datalen);
   hasher_Raw(hasher_type, data, datalen, hash);
@@ -205,6 +206,7 @@ int base58_decode_check(const char *str, HasherType hasher_type, uint8_t *data,
     return 0;
   }
   uint8_t d[datalen + 4];
+  memset(d, 0, sizeof(d));
   size_t res = datalen + 4;
   if (b58tobin(d, &res, str) != true) {
     return 0;
@@ -241,6 +243,7 @@ int base58gph_encode_check(const uint8_t *data, int datalen, char *str,
     return 0;
   }
   uint8_t buf[datalen + 32];
+  memset(buf, 0, sizeof(buf));
   uint8_t *hash = buf + datalen;
   memcpy(buf, data, datalen);
   ripemd160(data, datalen, hash);  // No double SHA256, but a single RIPEMD160
@@ -255,6 +258,7 @@ int base58gph_decode_check(const char *str, uint8_t *data, int datalen) {
     return 0;
   }
   uint8_t d[datalen + 4];
+  memset(d, 0, sizeof(d));
   size_t res = datalen + 4;
   if (b58tobin(d, &res, str) != true) {
     return 0;
diff --git a/crypto/monero/base58.c b/crypto/monero/base58.c
index 9979af69c..44da376e9 100644
--- a/crypto/monero/base58.c
+++ b/crypto/monero/base58.c
@@ -200,6 +200,7 @@ int xmr_base58_addr_encode_check(uint64_t tag, const uint8_t *data, size_t binsz
 
 	size_t b58size = b58sz;
 	uint8_t buf[(binsz + 1) + HASHER_DIGEST_LENGTH];
+	memset(buf, 0, sizeof(buf));
 	uint8_t *hash = buf + binsz + 1;
 	buf[0] = (uint8_t) tag;
 	memcpy(buf + 1, data, binsz);
@@ -213,6 +214,7 @@ int xmr_base58_addr_decode_check(const char *addr, size_t sz, uint64_t *tag, voi
 {
 	size_t buflen = 1 + 64 + addr_checksum_size;
 	uint8_t buf[buflen];
+	memset(buf, 0, sizeof(buf));
 	uint8_t hash[HASHER_DIGEST_LENGTH] = {0};
 
 	if (!xmr_base58_decode(addr, sz, buf, &buflen)){
diff --git a/crypto/shamir.c b/crypto/shamir.c
index 6c8893fac..ae94af1e0 100644
--- a/crypto/shamir.c
+++ b/crypto/shamir.c
@@ -267,7 +267,9 @@ bool shamir_interpolate(uint8_t *result, uint8_t result_index,
   size_t i = 0, j = 0;
   uint32_t x[8] = {0};
   uint32_t xs[share_count][8];
+  memset(xs, 0, sizeof(xs));
   uint32_t ys[share_count][8];
+  memset(ys, 0, sizeof(ys));
   uint32_t num[8] = {~0}; /* num is the numerator (=1) */
   uint32_t denom[8] = {0};
   uint32_t tmp[8] = {0};