diff --git a/include/zephyr/sys/util.h b/include/zephyr/sys/util.h
index a812ee4d37ea..fcfc178b459f 100644
--- a/include/zephyr/sys/util.h
+++ b/include/zephyr/sys/util.h
@@ -639,6 +639,45 @@ char *utf8_lcpy(char *dst, const char *src, size_t n);
 	(((buflen) != 0) &&                        \
 	((UINTPTR_MAX - (uintptr_t)(addr)) <= ((uintptr_t)((buflen) - 1))))
 
+/**
+ * @brief XOR n bytes
+ *
+ * @param dst  Destination of where to store result. Shall be @p len bytes.
+ * @param src1 First source. Shall be @p len bytes.
+ * @param src2 Second source. Shall be @p len bytes.
+ * @param len  Number of bytes to XOR.
+ */
+static inline void mem_xor_n(uint8_t *dst, const uint8_t *src1, const uint8_t *src2, size_t len)
+{
+	while (len--) {
+		*dst++ = *src1++ ^ *src2++;
+	}
+}
+
+/**
+ * @brief XOR 32 bits
+ *
+ * @param dst  Destination of where to store result. Shall be 32 bits.
+ * @param src1 First source. Shall be 32 bits.
+ * @param src2 Second source. Shall be 32 bits.
+ */
+static inline void mem_xor_32(uint8_t dst[4], const uint8_t src1[4], const uint8_t src2[4])
+{
+	mem_xor_n(dst, src1, src2, 4U);
+}
+
+/**
+ * @brief XOR 128 bits
+ *
+ * @param dst  Destination of where to store result. Shall be 128 bits.
+ * @param src1 First source. Shall be 128 bits.
+ * @param src2 Second source. Shall be 128 bits.
+ */
+static inline void mem_xor_128(uint8_t dst[16], const uint8_t src1[16], const uint8_t src2[16])
+{
+	mem_xor_n(dst, src1, src2, 16);
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/subsys/bluetooth/audio/csip_crypto.c b/subsys/bluetooth/audio/csip_crypto.c
index d51855f02a58..d880ca36ce1d 100644
--- a/subsys/bluetooth/audio/csip_crypto.c
+++ b/subsys/bluetooth/audio/csip_crypto.c
@@ -17,6 +17,7 @@
 #include <tinycrypt/cmac_mode.h>
 #include <tinycrypt/ccm_mode.h>
 #include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/util.h>
 
 #include "common/bt_str.h"
 
@@ -51,16 +52,6 @@ static int aes_cmac(const uint8_t key[BT_CSIP_CRYPTO_KEY_SIZE],
 	return 0;
 }
 
-static void xor_128(const uint8_t a[16], const uint8_t b[16], uint8_t out[16])
-{
-	size_t len = 16;
-	/* TODO: Identical to the xor_128 from smp.c: Move to util */
-
-	while (len--) {
-		*out++ = *a++ ^ *b++;
-	}
-}
-
 int bt_csip_sih(const uint8_t sirk[BT_CSIP_SET_SIRK_SIZE], uint8_t r[BT_CSIP_CRYPTO_PRAND_SIZE],
 		uint8_t out[BT_CSIP_CRYPTO_HASH_SIZE])
 {
@@ -229,7 +220,7 @@ int bt_csip_sef(const uint8_t k[BT_CSIP_CRYPTO_KEY_SIZE],
 		sys_mem_swap(k1_out, sizeof(k1_out));
 	}
 
-	xor_128(k1_out, sirk, out_sirk);
+	mem_xor_128(out_sirk, k1_out, sirk);
 	LOG_DBG("out %s", bt_hex(out_sirk, BT_CSIP_SET_SIRK_SIZE));
 
 	return 0;
diff --git a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_adv_iso.c b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_adv_iso.c
index 20e3fe528e1c..f5e566a7bccb 100644
--- a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_adv_iso.c
+++ b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_adv_iso.c
@@ -9,6 +9,7 @@
 
 #include <soc.h>
 #include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/util.h>
 
 #include "hal/cpu.h"
 #include "hal/ccm.h"
diff --git a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync_iso.c b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync_iso.c
index 12e9fd342b97..d4611425f2c2 100644
--- a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync_iso.c
+++ b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync_iso.c
@@ -9,6 +9,7 @@
 
 #include <soc.h>
 #include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/util.h>
 
 #include "hal/cpu.h"
 #include "hal/ccm.h"
diff --git a/subsys/bluetooth/controller/ll_sw/ull_conn_iso.c b/subsys/bluetooth/controller/ll_sw/ull_conn_iso.c
index 2ec6a73b4a4b..467460d2f30b 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_conn_iso.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_conn_iso.c
@@ -6,6 +6,7 @@
 
 #include <zephyr/kernel.h>
 #include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/util.h>
 #include <zephyr/bluetooth/hci_types.h>
 
 #include "util/util.h"
diff --git a/subsys/bluetooth/controller/util/mem.c b/subsys/bluetooth/controller/util/mem.c
index 1bd67ee7eb19..e0450ac815bc 100644
--- a/subsys/bluetooth/controller/util/mem.c
+++ b/subsys/bluetooth/controller/util/mem.c
@@ -134,24 +134,6 @@ uint8_t mem_nz(uint8_t *src, uint16_t len)
 	return 0;
 }
 
-/**
- * @brief XOR bytes
- */
-inline void mem_xor_n(uint8_t *dst, uint8_t *src1, uint8_t *src2, uint16_t len)
-{
-	while (len--) {
-		*dst++ = *src1++ ^ *src2++;
-	}
-}
-
-/**
- * @brief XOR 32-bits
- */
-void mem_xor_32(uint8_t *dst, uint8_t *src1, uint8_t *src2)
-{
-	mem_xor_n(dst, src1, src2, 4U);
-}
-
 /**
  * @brief Unit test
  */
diff --git a/subsys/bluetooth/controller/util/mem.h b/subsys/bluetooth/controller/util/mem.h
index 8a8bdb3a62d7..4a345ab253f4 100644
--- a/subsys/bluetooth/controller/util/mem.h
+++ b/subsys/bluetooth/controller/util/mem.h
@@ -63,7 +63,5 @@ uint16_t mem_index_get(const void *mem, const void *mem_pool, uint16_t mem_size)
 
 void mem_rcopy(uint8_t *dst, uint8_t const *src, uint16_t len);
 uint8_t mem_nz(uint8_t *src, uint16_t len);
-void mem_xor_n(uint8_t *dst, uint8_t *src1, uint8_t *src2, uint16_t len);
-void mem_xor_32(uint8_t *dst, uint8_t *src1, uint8_t *src2);
 
 uint32_t mem_ut(void);
diff --git a/subsys/bluetooth/host/smp.c b/subsys/bluetooth/host/smp.c
index 2c110dc43a38..95809d237686 100644
--- a/subsys/bluetooth/host/smp.c
+++ b/subsys/bluetooth/host/smp.c
@@ -1829,15 +1829,6 @@ static uint8_t smp_send_pairing_random(struct bt_smp *smp)
 }
 
 #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
-static void xor_128(const uint8_t p[16], const uint8_t q[16], uint8_t r[16])
-{
-	size_t len = 16;
-
-	while (len--) {
-		*r++ = *p++ ^ *q++;
-	}
-}
-
 static int smp_c1(const uint8_t k[16], const uint8_t r[16],
 		  const uint8_t preq[7], const uint8_t pres[7],
 		  const bt_addr_le_t *ia, const bt_addr_le_t *ra,
@@ -1864,7 +1855,7 @@ static int smp_c1(const uint8_t k[16], const uint8_t r[16],
 	/* c1 = e(k, e(k, r XOR p1) XOR p2) */
 
 	/* Using enc_data as temporary output buffer */
-	xor_128(r, p1, enc_data);
+	mem_xor_128(enc_data, r, p1);
 
 	err = bt_encrypt_le(k, enc_data, enc_data);
 	if (err) {
@@ -1878,7 +1869,7 @@ static int smp_c1(const uint8_t k[16], const uint8_t r[16],
 
 	LOG_DBG("p2 %s", bt_hex(p2, 16));
 
-	xor_128(enc_data, p2, enc_data);
+	mem_xor_128(enc_data, p2, enc_data);
 
 	return bt_encrypt_le(k, enc_data, enc_data);
 }
diff --git a/tests/unit/util/main.c b/tests/unit/util/main.c
index c1dbca35bdcc..b9d1cdedf52a 100644
--- a/tests/unit/util/main.c
+++ b/tests/unit/util/main.c
@@ -618,4 +618,75 @@ ZTEST(util, test_IF_DISABLED)
 	#undef test_IF_DISABLED_FLAG_B
 }
 
+ZTEST(util, test_mem_xor_n)
+{
+	const size_t max_len = 128;
+	uint8_t expected_result[max_len];
+	uint8_t src1[max_len];
+	uint8_t src2[max_len];
+	uint8_t dst[max_len];
+
+	memset(expected_result, 0, sizeof(expected_result));
+	memset(src1, 0, sizeof(src1));
+	memset(src2, 0, sizeof(src2));
+	memset(dst, 0, sizeof(dst));
+
+	for (size_t i = 0U; i < max_len; i++) {
+		const size_t len = i;
+
+		for (size_t j = 0U; j < len; j++) {
+			src1[j] = 0x33;
+			src2[j] = 0x0F;
+			expected_result[j] = 0x3C;
+		}
+
+		mem_xor_n(dst, src1, src2, len);
+		zassert_mem_equal(expected_result, dst, len);
+	}
+}
+
+ZTEST(util, test_mem_xor_32)
+{
+	uint8_t expected_result[4];
+	uint8_t src1[4];
+	uint8_t src2[4];
+	uint8_t dst[4];
+
+	memset(expected_result, 0, sizeof(expected_result));
+	memset(src1, 0, sizeof(src1));
+	memset(src2, 0, sizeof(src2));
+	memset(dst, 0, sizeof(dst));
+
+	for (size_t i = 0U; i < 4; i++) {
+		src1[i] = 0x43;
+		src2[i] = 0x0F;
+		expected_result[i] = 0x4C;
+	}
+
+	mem_xor_32(dst, src1, src2);
+	zassert_mem_equal(expected_result, dst, 4);
+}
+
+ZTEST(util, test_mem_xor_128)
+{
+	uint8_t expected_result[16];
+	uint8_t src1[16];
+	uint8_t src2[16];
+	uint8_t dst[16];
+
+	memset(expected_result, 0, sizeof(expected_result));
+	memset(src1, 0, sizeof(src1));
+	memset(src2, 0, sizeof(src2));
+	memset(dst, 0, sizeof(dst));
+
+	for (size_t i = 0U; i < 16; i++) {
+		src1[i] = 0x53;
+		src2[i] = 0x0F;
+		expected_result[i] = 0x5C;
+	}
+
+	mem_xor_128(dst, src1, src2);
+	zassert_mem_equal(expected_result, dst, 16);
+}
+
 ZTEST_SUITE(util, NULL, NULL, NULL, NULL, NULL);