diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a95d08f3..13063c04 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -384,12 +384,16 @@ jobs:
         set -o xtrace
         go test -v test-via-pcsc/piv_test.go
         RDID="Canokey [OpenPGP PIV OATH] 00 00"
+        export PIV_EXT_AUTH_KEY=$PWD/test-via-pcsc/PIV_EXT_AUTH_KEY.txt 
         yubico-piv-tool -r "$RDID" -a status -a set-ccc -a set-chuid -a status
         opensc-tool -r "$RDID" -s '00 F8 00 00' | grep 'SW1=0x90, SW2=0x00' # PIV_INS_GET_SERIAL, Yubico
         opensc-tool -r "$RDID" -s '00 FD 00 00' | grep 'SW1=0x90, SW2=0x00' # PIV_INS_GET_VERSION, Yubico
         pkcs15-tool --reader "$RDID" -D
 
+        # change the algorithm identifier of ED25519
+        piv-tool --admin M:9B:03 -s '00 EE 02 00 07 01 22 05 51 52 53 54' | grep 'SW1=0x90, SW2=0x00' # PIV_INS_ALGORITHM_EXTENSION, Yubico
         cd piv-go; go test -v ./piv --wipe-yubikey; cd -
+        piv-tool --admin M:9B:03 -s '00 EE 02 00 07 01 E0 05 16 E1 53 54' | grep 'SW1=0x90, SW2=0x00' # PIV_INS_ALGORITHM_EXTENSION, Yubico
 
         yubico-piv-tool -r "$RDID" -a verify-pin -P 123456
         yubico-piv-tool -r "$RDID" -a change-pin -P 123456 -N 654321
@@ -399,7 +403,6 @@ jobs:
         yubico-piv-tool -r "$RDID" -a verify-pin -P 654321
         yubico-piv-tool -r "$RDID" -a set-mgm-key -n F1F2F3F4F5F6F7F8F1F2F3F4F5F6F7F8F1F2F3F4F5F6F7F8
         yubico-piv-tool -r "$RDID" -a set-mgm-key --key=F1F2F3F4F5F6F7F8F1F2F3F4F5F6F7F8F1F2F3F4F5F6F7F8 -n 010203040506070801020304050607080102030405060708
-        export PIV_EXT_AUTH_KEY=$PWD/test-via-pcsc/PIV_EXT_AUTH_KEY.txt 
         # opensc 0.22.0~0.23.0 has a bug on External Auth. See opensc commit: a0aef25c7f2ce0ec2c7e1014f959f0fe86ff0479
         piv-tool --reader "$RDID" --admin A:9B:03  # External Auth
         piv-tool --reader "$RDID" --admin M:9B:03  # Mutual Auth
diff --git a/applets/piv/piv.c b/applets/piv/piv.c
index 92908071..469f950e 100644
--- a/applets/piv/piv.c
+++ b/applets/piv/piv.c
@@ -41,10 +41,10 @@
 #define ALG_RSA_2048  0x07
 #define ALG_ECC_256   0x11
 #define ALG_ECC_384   0x14
-#define ALG_ED25519_DEFAULT   0x22 // defined in https://github.com/go-piv/piv-go/pull/69
+#define ALG_ED25519_DEFAULT   0xE0
 #define ALG_RSA_3072_DEFAULT  0x05 // defined in NIST SP 800-78-5 (Initial Public Draft)
-#define ALG_RSA_4096_DEFAULT  0x51
-#define ALG_X25519_DEFAULT    0x52
+#define ALG_RSA_4096_DEFAULT  0x16
+#define ALG_X25519_DEFAULT    0xE1
 #define ALG_SECP256K1_DEFAULT 0x53
 #define ALG_SM2_DEFAULT       0x54
 
@@ -253,7 +253,8 @@ int piv_install(const uint8_t reset) {
   if (write_attr(pin.path, TAG_PIN_KEY_DEFAULT, &tmp, sizeof(tmp)) < 0) return -1;
   if (pin_create(&puk, DEFAULT_PUK, 8, 3) < 0) return -1;
   if (write_attr(puk.path, TAG_PIN_KEY_DEFAULT, &tmp, sizeof(tmp)) < 0) return -1;
-
+  
+  if (get_file_size(ALGORITHM_EXT_CONFIG_PATH) == sizeof(alg_ext_cfg))  return 0;
   // Algorithm extensions
   alg_ext_cfg.enabled = 1;
   alg_ext_cfg.ed25519 = ALG_ED25519_DEFAULT;
@@ -1099,7 +1100,7 @@ static int piv_get_version(const CAPDU *capdu, RAPDU *rapdu) {
   if (P1 != 0x00 || P2 != 0x00) EXCEPT(SW_WRONG_P1P2);
   if (LC != 0) EXCEPT(SW_WRONG_LENGTH);
   RDATA[0] = 0x05;
-  RDATA[1] = 0x04;
+  RDATA[1] = 0x07;
   RDATA[2] = 0x00;
   LL = 3;
   return 0;
diff --git a/test-real/test-piv.sh b/test-real/test-piv.sh
index cac821f7..3ecad0c6 100755
--- a/test-real/test-piv.sh
+++ b/test-real/test-piv.sh
@@ -15,6 +15,7 @@ PIVGenKeyCert() {
     algo="$3"
     YPT -a generate -A $algo -s $key >$TEST_TMP_DIR/pubkey-$key.pem # generate key at $key
     assertEquals 'yubico-piv-tool generate' 0 $?
+    if [[ $algo == "X25519" ]]; then return; fi
     YPT -P 654321 -a verify-pin -a selfsign-certificate -s $key -S "$subject" < $TEST_TMP_DIR/pubkey-$key.pem >$TEST_TMP_DIR/cert-$key.pem
     assertEquals 'yubico-piv-tool selfsign-certificate' 0 $?
     YPT -a import-certificate -s $key < $TEST_TMP_DIR/cert-$key.pem
@@ -36,13 +37,15 @@ PIVSignDec() {
     key=$1
     pinArgs=
     op=$3
+    inp_file=$TEST_TMP_DIR/cert-$key.pem
+    if [[ $key == X25519 ]]; then inp_file=$TEST_TMP_DIR/pubkey-$key.pem; fi
     if [[ -n "$2" ]]; then pinArgs="-P 654321 -a verify-pin"; fi
     if [[ -z "$op" || s = "$op" ]]; then 
-        YPT $pinArgs -a test-signature -s $key < $TEST_TMP_DIR/cert-$key.pem;
+        YPT $pinArgs -a test-signature -s $key < $inp_file;
         assertEquals 'yubico-piv-tool test-signature' 0 $?
     fi
     if [[ -z "$op" || d = "$op" ]]; then 
-        YPT $pinArgs -a test-decipher -s $key < $TEST_TMP_DIR/cert-$key.pem;
+        YPT $pinArgs -a test-decipher -s $key < $inp_file;
         assertEquals 'yubico-piv-tool test-decipher' 0 $?
     fi
 }
@@ -86,8 +89,8 @@ test_ChangePin() {
     assertEquals 'set-mgm-key' 0 $?
 }
 
-test_RSA2048() {
-    for s in 9a 9c 9d 9e; do PIVGenKeyCert $s "/CN=CertAtSlot$s/" RSA2048; done
+rsa_tests() {
+    for s in 9a 9c 9d 9e; do PIVGenKeyCert $s "/CN=CertAtSlot$s/" $1; done
     YPT -a status
     PIVSignDec 9e # PIN not required for key 9e
     for s in 9a 9c 9d; do PIVSignDec $s 1; done
@@ -101,22 +104,44 @@ test_RSA2048() {
     assertEquals 'openssl dgst verify' 0 $?
 }
 
-test_ECC256() {
-    for s in 9a 9c 9d 9e; do PIVGenKeyCert $s "/CN=CertAtSlot$s/" ECCP256; done
+test_RSA2048() {
+    rsa_tests RSA2048
+}
+
+test_RSA3072() {
+    rsa_tests RSA3072
+}
+
+test_RSA4096() {
+    rsa_tests RSA4096
+}
+
+ec_tests() {
+    for s in 9a 9c 9d 9e; do PIVGenKeyCert $s "/CN=CertAtSlot$s/" $1; done
     YPT -a status
-    for s in 9a 9c 9e; do PIVSignDec $s 1 s; done # 9a/9c/9e only do the ECDSA
-    PIVSignDec 9d 1 d # 9d only do the ECDH
-    out=$(pkcs15-tool --reader "$RDID" --read-certificate 01 | openssl x509 -text)
-    assertContains 'CERT' "$out" 'CN = CertAtSlot9a'
+    for s in 9a 9c 9d 9e; do
+        if [[ $1 != "X25519" ]]; then PIVSignDec $s 1 s; fi
+        if [[ $1 != "ED25519" ]]; then PIVSignDec $s 1 d; fi
+    done
+    if [[ $1 != *25519 ]]; then
+        out=$(pkcs15-tool --reader "$RDID" --read-certificate 01 | openssl x509 -text)
+        assertContains 'CERT' "$out" 'CN = CertAtSlot9a'
+        out=$(pkcs15-tool --reader "$RDID" --read-certificate 02 | openssl x509 -text)
+        assertContains 'CERT' "$out" 'CN = CertAtSlot9c'
+    fi
+}
+
+test_ECC256() {
+    ec_tests ECCP256
 }
 
 test_ECC384() {
-    for s in 9a 9c 9d 9e; do PIVGenKeyCert $s "/CN=CertAtSlot$s/" ECCP384; done
-    YPT -a status
-    for s in 9a 9c 9e; do PIVSignDec $s 1 s; done # 9a/9c/9e only do the ECDSA
-    PIVSignDec 9d 1 d # 9d only do the ECDH
-    out=$(pkcs15-tool --reader "$RDID" --read-certificate 02 | openssl x509 -text)
-    assertContains 'CERT' "$out" 'CN = CertAtSlot9c'
+    ec_tests ECCP384
+}
+
+test_25519() {
+    ec_tests ED25519
+    ec_tests X25519
 }
 
 test_PinBlock() {