diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 5558edc..9b4c44e 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -35,7 +35,7 @@ jobs:
         language: [ 'cpp', 'python' ]
         # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
         # Learn more about CodeQL language support at https://aka.ms/codeql-docs/language-support
-        mode: [ 'pico', 'esp32', 'local' ]
+        mode: [ 'pico', 'local' ]
 
     steps:
     - name: Checkout repository
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9f0b4ba..213100b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,10 +14,10 @@ name: "Emulation and test"
 on:
   workflow_dispatch:
   push:
-    branches: [ "main", "piv" ]
+    branches: [ "main", "piv", "eddsa" ]
   pull_request:
     # The branches below must be a subset of the branches above
-    branches: [ "main", "piv" ]
+    branches: [ "main", "piv", "eddsa" ]
   schedule:
     - cron: '23 5 * * 4'
 
diff --git a/build_pico_openpgp.sh b/build_pico_openpgp.sh
index 9f150f3..1d52c87 100755
--- a/build_pico_openpgp.sh
+++ b/build_pico_openpgp.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 VERSION_MAJOR="3"
-VERSION_MINOR="4"
+VERSION_MINOR="4-eddsa1"
 SUFFIX="${VERSION_MAJOR}.${VERSION_MINOR}"
 #if ! [[ -z "${GITHUB_SHA}" ]]; then
 #    SUFFIX="${SUFFIX}.${GITHUB_SHA}"
diff --git a/pico-keys-sdk b/pico-keys-sdk
index 07415e6..6ec374a 160000
--- a/pico-keys-sdk
+++ b/pico-keys-sdk
@@ -1 +1 @@
-Subproject commit 07415e6e8be36255fbcd3e5c3aeec394c7b76bac
+Subproject commit 6ec374a6ac53a4de34ed26ae19be126fe7c704e7
diff --git a/src/openpgp/CMakeLists.txt b/src/openpgp/CMakeLists.txt
index 31d66c9..a0fff70 100644
--- a/src/openpgp/CMakeLists.txt
+++ b/src/openpgp/CMakeLists.txt
@@ -1,6 +1,6 @@
 idf_component_register(
     SRCS ${SOURCES}
-    INCLUDE_DIRS . ../../pico-keys-sdk/src ../../pico-keys-sdk/src/fs ../../pico-keys-sdk/src/rng ../../pico-keys-sdk/src/usb
+    INCLUDE_DIRS . ../../pico-keys-sdk/src ../../pico-keys-sdk/src/fs ../../pico-keys-sdk/src/rng ../../pico-keys-sdk/src/usb ../../pico-keys-sdk/tinycbor/src
     REQUIRES bootloader_support esp_partition esp_tinyusb zorxx__neopixel mbedtls efuse
 )
 idf_component_set_property(${COMPONENT_NAME} WHOLE_ARCHIVE ON)
diff --git a/src/openpgp/cmd_import_data.c b/src/openpgp/cmd_import_data.c
index 74df4ec..e17df7d 100644
--- a/src/openpgp/cmd_import_data.c
+++ b/src/openpgp/cmd_import_data.c
@@ -156,8 +156,8 @@ int cmd_import_data() {
             return SW_EXEC_ERROR();
         }
     }
-    else if (algo[0] == ALGO_ECDSA || algo[0] == ALGO_ECDH) {
-        mbedtls_ecdsa_context ecdsa;
+    else if (algo[0] == ALGO_ECDSA || algo[0] == ALGO_ECDH || algo[0] == ALGO_EDDSA) {
+        mbedtls_ecp_keypair ecdsa;
         if (p[1] == NULL || len[1] == 0) {
             return SW_WRONG_DATA();
         }
@@ -165,7 +165,7 @@ int cmd_import_data() {
         if (gid == MBEDTLS_ECP_DP_NONE) {
             return SW_FUNC_NOT_SUPPORTED();
         }
-        mbedtls_ecdsa_init(&ecdsa);
+        mbedtls_ecp_keypair_init(&ecdsa);
         if (gid == MBEDTLS_ECP_DP_CURVE25519) {
             mbedtls_ecp_group_load(&ecdsa.grp, gid);
             r = mbedtls_mpi_read_binary(&ecdsa.d, p[1], len[1]);
@@ -174,17 +174,22 @@ int cmd_import_data() {
             r = mbedtls_ecp_read_key(gid, &ecdsa, p[1], len[1]);
         }
         if (r != 0) {
-            mbedtls_ecdsa_free(&ecdsa);
+            mbedtls_ecp_keypair_free(&ecdsa);
             return SW_EXEC_ERROR();
         }
-        r = mbedtls_ecp_mul(&ecdsa.grp, &ecdsa.Q, &ecdsa.d, &ecdsa.grp.G, random_gen, NULL);
+        if (ecdsa.grp.id == MBEDTLS_ECP_DP_ED25519) {
+            r = mbedtls_ecp_point_edwards(&ecdsa.grp, &ecdsa.Q, &ecdsa.d, random_gen, NULL);
+        }
+        else {
+            r = mbedtls_ecp_mul(&ecdsa.grp, &ecdsa.Q, &ecdsa.d, &ecdsa.grp.G, random_gen, NULL);
+        }
         if (r != 0) {
-            mbedtls_ecdsa_free(&ecdsa);
+            mbedtls_ecp_keypair_free(&ecdsa);
             return SW_EXEC_ERROR();
         }
         r = store_keys(&ecdsa, ALGO_ECDSA, fid, true);
         make_ecdsa_response(&ecdsa);
-        mbedtls_ecdsa_free(&ecdsa);
+        mbedtls_ecp_keypair_free(&ecdsa);
         if (r != PICOKEY_OK) {
             return SW_EXEC_ERROR();
         }
diff --git a/src/openpgp/cmd_internal_aut.c b/src/openpgp/cmd_internal_aut.c
index 92d4c07..869bb22 100644
--- a/src/openpgp/cmd_internal_aut.c
+++ b/src/openpgp/cmd_internal_aut.c
@@ -57,17 +57,17 @@ int cmd_internal_aut() {
         }
         res_APDU_size = olen;
     }
-    else if (algo[0] == ALGO_ECDH || algo[0] == ALGO_ECDSA) {
-        mbedtls_ecdsa_context ctx;
-        mbedtls_ecdsa_init(&ctx);
+    else if (algo[0] == ALGO_ECDH || algo[0] == ALGO_ECDSA || algo[0] == ALGO_EDDSA) {
+        mbedtls_ecp_keypair ctx;
+        mbedtls_ecp_keypair_init(&ctx);
         r = load_private_key_ecdsa(&ctx, ef, true);
         if (r != PICOKEY_OK) {
-            mbedtls_ecdsa_free(&ctx);
+            mbedtls_ecp_keypair_free(&ctx);
             return SW_EXEC_ERROR();
         }
         size_t olen = 0;
         r = ecdsa_sign(&ctx, apdu.data, apdu.nc, res_APDU, &olen);
-        mbedtls_ecdsa_free(&ctx);
+        mbedtls_ecp_keypair_free(&ctx);
         if (r != 0) {
             return SW_EXEC_ERROR();
         }
diff --git a/src/openpgp/cmd_keypair_gen.c b/src/openpgp/cmd_keypair_gen.c
index 9329350..23a91a4 100644
--- a/src/openpgp/cmd_keypair_gen.c
+++ b/src/openpgp/cmd_keypair_gen.c
@@ -76,23 +76,23 @@ int cmd_keypair_gen() {
                 return SW_EXEC_ERROR();
             }
         }
-        else if (algo[0] == ALGO_ECDH || algo[0] == ALGO_ECDSA) {
+        else if (algo[0] == ALGO_ECDH || algo[0] == ALGO_ECDSA || algo[0] == ALGO_EDDSA) {
             printf("KEYPAIR ECDSA\r\n");
             mbedtls_ecp_group_id gid = get_ec_group_id_from_attr(algo + 1, algo_len - 1);
             if (gid == MBEDTLS_ECP_DP_NONE) {
                 return SW_FUNC_NOT_SUPPORTED();
             }
-            mbedtls_ecdsa_context ecdsa;
-            mbedtls_ecdsa_init(&ecdsa);
+            mbedtls_ecp_keypair ecdsa;
+            mbedtls_ecp_keypair_init(&ecdsa);
             uint8_t index = 0;
             r = mbedtls_ecdsa_genkey(&ecdsa, gid, random_gen, &index);
             if (r != 0) {
-                mbedtls_ecdsa_free(&ecdsa);
+                mbedtls_ecp_keypair_free(&ecdsa);
                 return SW_EXEC_ERROR();
             }
             r = store_keys(&ecdsa, algo[0], fid, true);
             make_ecdsa_response(&ecdsa);
-            mbedtls_ecdsa_free(&ecdsa);
+            mbedtls_ecp_keypair_free(&ecdsa);
             if (r != PICOKEY_OK) {
                 return SW_EXEC_ERROR();
             }
diff --git a/src/openpgp/cmd_pso.c b/src/openpgp/cmd_pso.c
index fd5a891..e2e9ba0 100644
--- a/src/openpgp/cmd_pso.c
+++ b/src/openpgp/cmd_pso.c
@@ -137,18 +137,18 @@ int cmd_pso() {
             res_APDU_size = olen;
         }
     }
-    else if (algo[0] == ALGO_ECDH || algo[0] == ALGO_ECDSA) {
+    else if (algo[0] == ALGO_ECDH || algo[0] == ALGO_ECDSA || algo[0] == ALGO_EDDSA) {
         if (P1(apdu) == 0x9E && P2(apdu) == 0x9A) {
-            mbedtls_ecdsa_context ctx;
-            mbedtls_ecdsa_init(&ctx);
+            mbedtls_ecp_keypair ctx;
+            mbedtls_ecp_keypair_init(&ctx);
             r = load_private_key_ecdsa(&ctx, ef, true);
             if (r != PICOKEY_OK) {
-                mbedtls_ecdsa_free(&ctx);
+                mbedtls_ecp_keypair_free(&ctx);
                 return SW_EXEC_ERROR();
             }
             size_t olen = 0;
             r = ecdsa_sign(&ctx, apdu.data, apdu.nc, res_APDU, &olen);
-            mbedtls_ecdsa_free(&ctx);
+            mbedtls_ecp_keypair_free(&ctx);
             if (r != 0) {
                 return SW_EXEC_ERROR();
             }
diff --git a/src/openpgp/do.c b/src/openpgp/do.c
index 28b0a72..0f76bc0 100644
--- a/src/openpgp/do.c
+++ b/src/openpgp/do.c
@@ -275,6 +275,12 @@ const uint8_t algorithm_attr_cv25519[] = {
     0x2b, 0x06, 0x01, 0x04, 0x01, 0x97, 0x55, 0x01, 0x05, 0x01
 };
 
+const uint8_t algorithm_attr_ed25519[] = {
+    10,
+    ALGO_EDDSA,
+    0x2b, 0x06, 0x01, 0x04, 0x01, 0xda, 0x47, 0x0f, 0x01
+};
+
 int parse_algo(const uint8_t *algo, uint16_t tag) {
     res_APDU[res_APDU_size++] = tag & 0xff;
     memcpy(res_APDU + res_APDU_size, algo, algo[0] + 1);
@@ -300,6 +306,7 @@ int parse_algoinfo(const file_t *f, int mode) {
         datalen += parse_algo(algorithm_attr_bp256r1, EF_ALGO_SIG);
         datalen += parse_algo(algorithm_attr_bp384r1, EF_ALGO_SIG);
         datalen += parse_algo(algorithm_attr_bp512r1, EF_ALGO_SIG);
+        datalen += parse_algo(algorithm_attr_ed25519, EF_ALGO_SIG);
 
         datalen += parse_algo(algorithm_attr_rsa1k, EF_ALGO_DEC);
         datalen += parse_algo(algorithm_attr_rsa2k, EF_ALGO_DEC);
@@ -326,6 +333,7 @@ int parse_algoinfo(const file_t *f, int mode) {
         datalen += parse_algo(algorithm_attr_bp256r1, EF_ALGO_AUT);
         datalen += parse_algo(algorithm_attr_bp384r1, EF_ALGO_AUT);
         datalen += parse_algo(algorithm_attr_bp512r1, EF_ALGO_AUT);
+        datalen += parse_algo(algorithm_attr_ed25519, EF_ALGO_AUT);
         uint16_t lpdif = res_APDU + res_APDU_size - lp - 2;
         *lp++ = lpdif >> 8;
         *lp++ = lpdif & 0xff;
diff --git a/src/openpgp/do.h b/src/openpgp/do.h
index 1a34242..d340fdb 100644
--- a/src/openpgp/do.h
+++ b/src/openpgp/do.h
@@ -26,3 +26,4 @@ extern const uint8_t algorithm_attr_cv25519[];
 extern const uint8_t algorithm_attr_x448[];
 extern const uint8_t algorithm_attr_rsa2k[];
 extern const uint8_t algorithm_attr_rsa4096[];
+extern const uint8_t algorithm_attr_ed25519[];
diff --git a/src/openpgp/openpgp.c b/src/openpgp/openpgp.c
index 6a55d00..0b30b7a 100644
--- a/src/openpgp/openpgp.c
+++ b/src/openpgp/openpgp.c
@@ -30,6 +30,7 @@
 #include "ccid/ccid.h"
 #include "otp.h"
 #include "do.h"
+#include "mbedtls/eddsa.h"
 
 uint8_t PICO_PRODUCT = 3;
 
@@ -488,8 +489,8 @@ int store_keys(void *key_ctx, int type, uint16_t key_id, bool use_kek) {
         mbedtls_mpi_write_binary(&rsa->P, kdata, key_size / 2);
         mbedtls_mpi_write_binary(&rsa->Q, kdata + key_size / 2, key_size / 2);
     }
-    else if (type == ALGO_ECDSA || type == ALGO_ECDH) {
-        mbedtls_ecdsa_context *ecdsa = (mbedtls_ecdsa_context *) key_ctx;
+    else if (type == ALGO_ECDSA || type == ALGO_ECDH || type == ALGO_EDDSA) {
+        mbedtls_ecp_keypair *ecdsa = (mbedtls_ecp_keypair *) key_ctx;
         size_t olen = 0;
         kdata[0] = ecdsa->grp.id & 0xff;
         mbedtls_ecp_write_key_ext(ecdsa, &olen, kdata + 1, sizeof(kdata) - 1);
@@ -558,7 +559,7 @@ int load_private_key_rsa(mbedtls_rsa_context *ctx, file_t *fkey, bool use_dek) {
     return PICOKEY_OK;
 }
 
-int load_private_key_ecdsa(mbedtls_ecdsa_context *ctx, file_t *fkey, bool use_dek) {
+int load_private_key_ecdsa(mbedtls_ecp_keypair *ctx, file_t *fkey, bool use_dek) {
     int key_size = file_get_size(fkey);
     uint8_t kdata[67]; //Worst case, 521 bit + 1byte
     memcpy(kdata, file_get_data(fkey), key_size);
@@ -568,11 +569,16 @@ int load_private_key_ecdsa(mbedtls_ecdsa_context *ctx, file_t *fkey, bool use_de
     mbedtls_ecp_group_id gid = kdata[0];
     int r = mbedtls_ecp_read_key(gid, ctx, kdata + 1, key_size - 1);
     if (r != 0) {
-        mbedtls_ecdsa_free(ctx);
+        mbedtls_ecp_keypair_free(ctx);
         return PICOKEY_EXEC_ERROR;
     }
     mbedtls_platform_zeroize(kdata, sizeof(kdata));
-    r = mbedtls_ecp_mul(&ctx->grp, &ctx->Q, &ctx->d, &ctx->grp.G, random_gen, NULL);
+    if (ctx->grp.id == MBEDTLS_ECP_DP_ED25519) {
+        r = mbedtls_ecp_point_edwards(&ctx->grp, &ctx->Q, &ctx->d, random_gen, NULL);
+    }
+    else {
+        r = mbedtls_ecp_mul(&ctx->grp, &ctx->Q, &ctx->d, &ctx->grp.G, random_gen, NULL);
+    }
     if (r != 0) {
         mbedtls_ecdsa_free(ctx);
         return PICOKEY_EXEC_ERROR;
@@ -617,6 +623,9 @@ mbedtls_ecp_group_id get_ec_group_id_from_attr(const uint8_t *algo, size_t algo_
     else if (memcmp(algorithm_attr_x448 + 2, algo, algo_len) == 0) {
         return MBEDTLS_ECP_DP_CURVE448;
     }
+    else if (memcmp(algorithm_attr_ed25519 + 2, algo, algo_len) == 0) {
+        return MBEDTLS_ECP_DP_ED25519;
+    }
     return MBEDTLS_ECP_DP_NONE;
 }
 
@@ -635,7 +644,7 @@ void make_rsa_response(mbedtls_rsa_context *rsa) {
     put_uint16_t_be(res_APDU_size - 5, res_APDU + 3);
 }
 
-void make_ecdsa_response(mbedtls_ecdsa_context *ecdsa) {
+void make_ecdsa_response(mbedtls_ecp_keypair *ecdsa) {
     uint8_t pt[MBEDTLS_ECP_MAX_PT_LEN];
     size_t plen = 0;
     mbedtls_ecp_point_write_binary(&ecdsa->grp,
@@ -728,23 +737,30 @@ int rsa_sign(mbedtls_rsa_context *ctx,
     return r;
 }
 
-int ecdsa_sign(mbedtls_ecdsa_context *ctx,
+int ecdsa_sign(mbedtls_ecp_keypair *ctx,
                const uint8_t *data,
                size_t data_len,
                uint8_t *out,
                size_t *out_len) {
-    mbedtls_mpi ri, si;
-    mbedtls_mpi_init(&ri);
-    mbedtls_mpi_init(&si);
-    int r = mbedtls_ecdsa_sign(&ctx->grp, &ri, &si, &ctx->d, data, data_len, random_gen, NULL);
-    if (r == 0) {
-        size_t plen = (ctx->grp.nbits + 7) / 8;
-        mbedtls_mpi_write_binary(&ri, out, plen);
-        mbedtls_mpi_write_binary(&si, out + plen, plen);
-        *out_len = 2 * plen;
+
+    int r = 0;
+    if (ctx->grp.id == MBEDTLS_ECP_DP_ED25519) {
+        r = mbedtls_eddsa_write_signature(ctx, data, data_len, out, 64, out_len, MBEDTLS_EDDSA_PURE, NULL, 0, random_gen, NULL);
+    }
+    else {
+        mbedtls_mpi ri, si;
+        mbedtls_mpi_init(&ri);
+        mbedtls_mpi_init(&si);
+        r = mbedtls_ecdsa_sign(&ctx->grp, &ri, &si, &ctx->d, data, data_len, random_gen, NULL);
+        if (r == 0) {
+            size_t plen = (ctx->grp.nbits + 7) / 8;
+            mbedtls_mpi_write_binary(&ri, out, plen);
+            mbedtls_mpi_write_binary(&si, out + plen, plen);
+            *out_len = 2 * plen;
+        }
+        mbedtls_mpi_free(&ri);
+        mbedtls_mpi_free(&si);
     }
-    mbedtls_mpi_free(&ri);
-    mbedtls_mpi_free(&si);
     return r;
 }
 
diff --git a/src/openpgp/openpgp.h b/src/openpgp/openpgp.h
index 2072262..c08ff75 100644
--- a/src/openpgp/openpgp.h
+++ b/src/openpgp/openpgp.h
@@ -59,6 +59,7 @@ extern int pin_reset_retries(const file_t *pin, bool force);
 #define ALGO_RSA        0x01
 #define ALGO_ECDH       0x12
 #define ALGO_ECDSA      0x13
+#define ALGO_EDDSA      0x16
 #define ALGO_AES        0x70
 #define ALGO_AES_128    0x71
 #define ALGO_AES_192    0x72