diff --git a/ecdsa.c b/ecdsa.c
index 9db6885..5ac4e7b 100644
--- a/ecdsa.c
+++ b/ecdsa.c
@@ -254,7 +254,7 @@ out:
 
 /* returns values in s and r
    returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
-int buf_get_ecdsa_verify_params(buffer *buf,
+static int buf_get_ecdsa_verify_params(buffer *buf,
 			void *r, void* s) {
 	int ret = DROPBEAR_FAILURE;
 	unsigned int sig_len;
diff --git a/ecdsa.h b/ecdsa.h
index fa082ad..01cb134 100644
--- a/ecdsa.h
+++ b/ecdsa.h
@@ -26,8 +26,6 @@ void buf_put_ecdsa_pub_key(buffer *buf, ecc_key *key);
 void buf_put_ecdsa_priv_key(buffer *buf, ecc_key *key);
 enum signkey_type ecdsa_signkey_type(const ecc_key * key);
 
-int buf_get_ecdsa_verify_params(buffer *buf, void *r, void* s);
-
 void buf_put_ecdsa_sign(buffer *buf, const ecc_key *key, const buffer *data_buf);
 int buf_ecdsa_verify(buffer *buf, const ecc_key *key, const buffer *data_buf);
 /* Returns 1 on success */
diff --git a/sk-ecdsa.c b/sk-ecdsa.c
index 8ca6c0e..2d4a0ff 100644
--- a/sk-ecdsa.c
+++ b/sk-ecdsa.c
@@ -8,47 +8,22 @@
 #include "sk-ecdsa.h"
 
 int buf_sk_ecdsa_verify(buffer *buf, const ecc_key *key, const buffer *data_buf, const char* app, unsigned int applen) {
-	/* Based on libtomcrypt's ecc_verify_hash but without the asn1 */
-	int ret = DROPBEAR_FAILURE;
 	hash_state hs;
-	struct dropbear_ecc_curve *curve = NULL;
-	unsigned char hash[64];
 	unsigned char subhash[SHA256_HASH_SIZE];
-	buffer *sk_buffer = NULL;
+	buffer *sk_buffer = NULL, *sig_buffer = NULL;
 	unsigned char flags;
 	unsigned int counter;
-	ecc_point *mG = NULL, *mQ = NULL;
-	void *r = NULL, *s = NULL, *v = NULL, *w = NULL, *u1 = NULL, *u2 = NULL,
-		*e = NULL, *p = NULL, *m = NULL;
-	void *mp = NULL;
-
-	/* verify
-	 *
-	 * w  = s^-1 mod n
-	 * u1 = xw
-	 * u2 = rw
-	 * X = u1*G + u2*Q
-	 * v = X_x1 mod n
-	 * accept if v == r
-	 */
+	int ret;
 
 	TRACE(("buf_sk_ecdsa_verify"))
-	curve = curve_for_dp(key->dp);
 
-	mG = ltc_ecc_new_point();
-	mQ = ltc_ecc_new_point();
-	if (ltc_init_multi(&r, &s, &v, &w, &u1, &u2, &p, &e, &m, NULL) != CRYPT_OK
-		|| !mG
-		|| !mQ) {
-		dropbear_exit("ECC error");
-	}
-
-	if (buf_get_ecdsa_verify_params(buf, r, s) != DROPBEAR_SUCCESS) {
-		goto out;
-	}
+	/* from https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.u2f */
+	/* ecdsa signature to verify (r, s) */
+	sig_buffer = buf_getbuf(buf);
 
 	flags = buf_getbyte (buf);
 	counter = buf_getint (buf);
+	/* create the message to be signed */
 	sk_buffer = buf_new (2*SHA256_HASH_SIZE+5);
 	sha256_init (&hs);
 	sha256_process (&hs, app, applen);
@@ -61,114 +36,11 @@ int buf_sk_ecdsa_verify(buffer *buf, const ecc_key *key, const buffer *data_buf,
 	sha256_done (&hs, subhash);
 	buf_putbytes (sk_buffer, subhash, sizeof (subhash));
 
-	curve->hash_desc->init(&hs);
-	curve->hash_desc->process(&hs, sk_buffer->data, sk_buffer->len);
-	curve->hash_desc->done(&hs, hash);
+	ret = buf_ecdsa_verify(sig_buffer, key, sk_buffer);
+	buf_free(sk_buffer);
+	buf_free(sig_buffer);
 
-	if (ltc_mp.unsigned_read(e, hash, curve->hash_desc->hashsize) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* get the order */
-	if (ltc_mp.read_radix(p, (char *)key->dp->order, 16) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* get the modulus */
-	if (ltc_mp.read_radix(m, (char *)key->dp->prime, 16) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* check for zero */
-	if (ltc_mp.compare_d(r, 0) == LTC_MP_EQ
-		|| ltc_mp.compare_d(s, 0) == LTC_MP_EQ
-		|| ltc_mp.compare(r, p) != LTC_MP_LT
-		|| ltc_mp.compare(s, p) != LTC_MP_LT) {
-		goto out;
-	}
-
-   /*  w  = s^-1 mod n */
-	if (ltc_mp.invmod(s, p, w) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* u1 = ew */
-	if (ltc_mp.mulmod(e, w, p, u1) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* u2 = rw */
-	if (ltc_mp.mulmod(r, w, p, u2) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* find mG and mQ */
-	if (ltc_mp.read_radix(mG->x, (char *)key->dp->Gx, 16) != CRYPT_OK) {
-		goto out;
-	}
-	if (ltc_mp.read_radix(mG->y, (char *)key->dp->Gy, 16) != CRYPT_OK) {
-		goto out;
-	}
-	if (ltc_mp.set_int(mG->z, 1) != CRYPT_OK) {
-		goto out;
-	}
-
-	if (ltc_mp.copy(key->pubkey.x, mQ->x) != CRYPT_OK
-		|| ltc_mp.copy(key->pubkey.y, mQ->y) != CRYPT_OK
-		|| ltc_mp.copy(key->pubkey.z, mQ->z) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* compute u1*mG + u2*mQ = mG */
-	if (ltc_mp.ecc_mul2add == NULL) {
-		if (ltc_mp.ecc_ptmul(u1, mG, mG, m, 0) != CRYPT_OK) {
-			goto out;
-		}
-		if (ltc_mp.ecc_ptmul(u2, mQ, mQ, m, 0) != CRYPT_OK) {
-			goto out;
-		}
-
-		/* find the montgomery mp */
-		if (ltc_mp.montgomery_setup(m, &mp) != CRYPT_OK) {
-			goto out;
-		}
-
-		/* add them */
-		if (ltc_mp.ecc_ptadd(mQ, mG, mG, m, mp) != CRYPT_OK) {
-			goto out;
-		}
-
-		/* reduce */
-		if (ltc_mp.ecc_map(mG, m, mp) != CRYPT_OK) {
-			goto out;
-		}
-	} else {
-		/* use Shamir's trick to compute u1*mG + u2*mQ using half of the doubles */
-		if (ltc_mp.ecc_mul2add(mG, u1, mQ, u2, mG, m) != CRYPT_OK) {
-			goto out;
-		}
-	}
-
-   /* v = X_x1 mod n */
-	if (ltc_mp.mpdiv(mG->x, p, NULL, v) != CRYPT_OK) {
-		goto out;
-	}
-
-   /* does v == r */
-	if (ltc_mp.compare(v, r) == LTC_MP_EQ) {
-		ret = DROPBEAR_SUCCESS;
-	}
-
-out:
-	ltc_ecc_del_point(mG);
-	ltc_ecc_del_point(mQ);
-	ltc_deinit_multi(r, s, v, w, u1, u2, p, e, m, NULL);
-	if (mp != NULL) {
-		ltc_mp.montgomery_deinit(mp);
-	}
-	if (sk_buffer) {
-		buf_free(sk_buffer);
-	}
+	TRACE(("leave buf_sk_ecdsa_verify, ret=%d", ret))
 	return ret;
 }