diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 9fdb366..d6723b2 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -391,6 +391,55 @@
 /****************************************************************/
 
 #if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
+psa_ecc_family_t mbedtls_ecc_group_to_psa(mbedtls_ecp_group_id grpid,
+                                          size_t *bits)
+{
+    switch (grpid) {
+        case MBEDTLS_ECP_DP_SECP192R1:
+            *bits = 192;
+            return PSA_ECC_FAMILY_SECP_R1;
+        case MBEDTLS_ECP_DP_SECP224R1:
+            *bits = 224;
+            return PSA_ECC_FAMILY_SECP_R1;
+        case MBEDTLS_ECP_DP_SECP256R1:
+            *bits = 256;
+            return PSA_ECC_FAMILY_SECP_R1;
+        case MBEDTLS_ECP_DP_SECP384R1:
+            *bits = 384;
+            return PSA_ECC_FAMILY_SECP_R1;
+        case MBEDTLS_ECP_DP_SECP521R1:
+            *bits = 521;
+            return PSA_ECC_FAMILY_SECP_R1;
+        case MBEDTLS_ECP_DP_BP256R1:
+            *bits = 256;
+            return PSA_ECC_FAMILY_BRAINPOOL_P_R1;
+        case MBEDTLS_ECP_DP_BP384R1:
+            *bits = 384;
+            return PSA_ECC_FAMILY_BRAINPOOL_P_R1;
+        case MBEDTLS_ECP_DP_BP512R1:
+            *bits = 512;
+            return PSA_ECC_FAMILY_BRAINPOOL_P_R1;
+        case MBEDTLS_ECP_DP_CURVE25519:
+            *bits = 255;
+            return PSA_ECC_FAMILY_MONTGOMERY;
+        case MBEDTLS_ECP_DP_SECP192K1:
+            *bits = 192;
+            return PSA_ECC_FAMILY_SECP_K1;
+        case MBEDTLS_ECP_DP_SECP224K1:
+            *bits = 224;
+            return PSA_ECC_FAMILY_SECP_K1;
+        case MBEDTLS_ECP_DP_SECP256K1:
+            *bits = 256;
+            return PSA_ECC_FAMILY_SECP_K1;
+        case MBEDTLS_ECP_DP_CURVE448:
+            *bits = 448;
+            return PSA_ECC_FAMILY_MONTGOMERY;
+        default:
+            *bits = 0;
+            return 0;
+    }
+}
+
 mbedtls_ecp_group_id mbedtls_ecc_group_of_psa(psa_ecc_family_t curve,
                                               size_t bits,
                                               int bits_is_sloppy)