diff --git a/setup.sh b/setup.sh
index 2136a584..97c7d458 100755
--- a/setup.sh
+++ b/setup.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# Copyright 2019 Google LLC
+# Copyright 2019-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -40,7 +40,11 @@ check_command "$PIP"
 
 # Ensure we have certificates, keys, etc. so that the tests can run
 source tools/gen_key_materials.sh
-generate_crypto_materials N
+generate_pki N
+if [ ! -f "crypto_data/opensk.key" -o ! -f "crypto_data/opensk_cert.pem" ]
+then
+  generate_new_batch
+fi
 
 rustup show
 "$PIP" install --upgrade -r requirements.txt
diff --git a/tools/gen_key_materials.sh b/tools/gen_key_materials.sh
index 1feb704f..c248f768 100755
--- a/tools/gen_key_materials.sh
+++ b/tools/gen_key_materials.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# Copyright 2019 Google LLC
+# Copyright 2019-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,20 +13,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-generate_crypto_materials () {
-  # OpenSSL ext file location
-  local openssl_ext_file=tools/openssl.ext
+generate_pki () {
+  # Curve parameters
+  local ecparams_file=crypto_data/ecparams.pem
   # OpenSK AAGUID
   local aaguid_file=crypto_data/aaguid.txt
 
   # Root CA key pair and certificate
-  local ca_priv_key=crypto_data/opensk_ca.key
-  local ca_cert_name=crypto_data/opensk_ca
+  local ca_priv_key=crypto_data/ca/root-ca/private/root-ca.key
+  local ca_cert_name=crypto_data/ca/root-ca
 
-  # Attestation key pair and certificate that will be embedded into the
-  # firmware. The certificate will be signed by the Root CA.
-  local opensk_key=crypto_data/opensk.key
-  local opensk_cert_name=crypto_data/opensk_cert
+  # Signing CA key pair and certificate
+  local signing_ca_priv_key=crypto_data/ca/signing-ca/private/signing-ca.key
+  local signing_ca_cert_name=crypto_data/ca/signing-ca
 
   # The upgrade private key is used for signing, the corresponding public key
   # will be COSE encoded and embedded into the firmware.
@@ -36,6 +35,9 @@ generate_crypto_materials () {
   # Allow invoker to override the command with a full path.
   local openssl=${OPENSSL:-$(which openssl)}
 
+  # Print version for debug purposes
+  ${openssl} version
+
   # We need openssl command to continue
   if [ ! -x "${openssl}" ]
   then
@@ -47,55 +49,109 @@ generate_crypto_materials () {
   set -e
 
   force_generate="$1"
-  mkdir -p crypto_data
-  if [ ! -f "${ca_priv_key}" ]
+  ask_for_password="$2"
+
+  if [ "${force_generate}" = "Y" ]
+  then
+    # Remove old OpenSK certs and CRL
+    rm -rf crypto_data/crl crypto_data/certs
+  fi
+
+  openssl_keypwd="-nodes"
+  openssl_batch="-batch"
+  if [ "${ask_for_password}" = "Y" ]
+  then
+    openssl_keypwd=""
+    openssl_batch=""
+  fi
+
+  # Create PKI directories
+  mkdir -p crypto_data/ca/root-ca/private crypto_data/ca/root-ca/db
+  mkdir -p crypto_data/ca/signing-ca/private crypto_data/ca/signing-ca/db
+  mkdir -p crypto_data/crl crypto_data/certs
+  chmod 700 crypto_data/ca/root-ca/private crypto_data/ca/signing-ca/private
+
+  # Prepare PKI databases
+  for fname in \
+    crypto_data/ca/root-ca/db/root-ca.db \
+    crypto_data/ca/root-ca/db/root-ca.db.attr \
+    crypto_data/ca/signing-ca/db/signing-ca.db \
+    crypto_data/ca/signing-ca/db/signing-ca.db.attr
+  do
+    if [ "${force_generate}" = "Y" -o ! -f "${fname}" ]
+    then
+      cp /dev/null "${fname}"
+    fi
+  done
+
+  # Initialize PKI serial numbers
+  for fname in \
+    crypto_data/ca/root-ca/db/root-ca.pem.srl \
+    crypto_data/ca/root-ca/db/root-ca.pem.srl \
+    crypto_data/ca/signing-ca/db/signing-ca.pem.srl \
+    crypto_data/ca/signing-ca/db/signing-ca.pem.srl
+  do
+    if [ "${force_generate}" = "Y" -o ! -f "${fname}" ]
+    then
+      echo 01 > "${fname}"
+    fi
+  done
+
+  # Generate AAGUID
+  if [ "${force_generate}" = "Y" -o ! -f "${aaguid_file}" ]
   then
-    "${openssl}" ecparam -genkey -name prime256v1 -out "${ca_priv_key}"
+    uuidgen > "${aaguid_file}"
+  fi
+
+  if [ ! -f "${ecparams_file}" ]
+  then
+    "${openssl}" ecparam -param_enc "named_curve" -name "prime256v1" -out "${ecparams_file}"
   fi
 
-  if [ ! -f "${ca_cert_name}.pem" ]
+  if [ "${force_generate}" = "Y" -o ! -f "${ca_cert_name}.pem" ]
   then
+    # Create root CA request and key pair
     "${openssl}" req \
       -new \
-      -key "${ca_priv_key}" \
+      -config tools/openssl/root-ca.conf \
       -out "${ca_cert_name}.csr" \
-      -subj "/CN=OpenSK CA"
-    "${openssl}" x509 \
-      -trustout \
-      -req \
-      -days 7305 \
+      -keyout "${ca_priv_key}" \
+      "${openssl_keypwd}" \
+      "${openssl_batch}" \
+      -newkey "ec:${ecparams_file}"
+    
+    # Make root CA certificate
+    "${openssl}" ca \
+      -selfsign \
+      -config tools/openssl/root-ca.conf \
+      "${openssl_batch}" \
       -in "${ca_cert_name}.csr" \
-      -signkey "${ca_priv_key}" \
-      -outform pem \
       -out "${ca_cert_name}.pem" \
-      -sha256
-  fi
-
-  if [ "${force_generate}" = "Y" -o ! -f "${opensk_key}" ]
-  then
-    "${openssl}" ecparam -genkey -name prime256v1 -out "${opensk_key}"
+      -extensions root_ca_ext
   fi
 
-  if [ "${force_generate}" = "Y" -o ! -f "${opensk_cert_name}.pem" ]
+  if [ "${force_generate}" = "Y" -o ! -f "${signing_ca_cert_name}.pem" ]
   then
+    # Create signing CA request
     "${openssl}" req \
       -new \
-      -key "${opensk_key}" \
-      -out "${opensk_cert_name}.csr" \
-      -subj "/C=US/O=OpenSK/OU=Authenticator Attestation/CN=OpenSK Hacker Edition"
-    "${openssl}" x509 \
-      -req \
-      -days 3652 \
-      -in "${opensk_cert_name}.csr" \
-      -CA "${ca_cert_name}.pem" \
-      -extfile "${openssl_ext_file}" \
-      -CAkey "${ca_priv_key}" \
-      -CAcreateserial \
-      -outform pem \
-      -out "${opensk_cert_name}.pem" \
-      -sha256
+      -config tools/openssl/signing-ca.conf \
+      -out "${signing_ca_cert_name}.csr" \
+      -keyout "${signing_ca_priv_key}" \
+      "${openssl_keypwd}" \
+      "${openssl_batch}" \
+      -newkey "ec:${ecparams_file}"
+
+    # Make signing CA certificate
+    "${openssl}" ca \
+      -config tools/openssl/root-ca.conf \
+      "${openssl_batch}" \
+      -in "${signing_ca_cert_name}.csr" \
+      -out "${signing_ca_cert_name}.pem" \
+      -extensions signing_ca_ext
   fi
 
+  # Create firmware update key pair
   if [ "${force_generate}" = "Y" -o ! -f "${opensk_upgrade}" ]
   then
     "${openssl}" ecparam -genkey -name prime256v1 -out "${opensk_upgrade}"
@@ -106,11 +162,88 @@ generate_crypto_materials () {
   then
     "${openssl}" ec -in "${opensk_upgrade}" -pubout -out "${opensk_upgrade_pub}"
   fi
+}
 
-  if [ "${force_generate}" = "Y" -o ! -f "${aaguid_file}" ]
+generate_new_batch () {
+  local openssl=${OPENSSL:-$(which openssl)}
+  # Curve parameters
+  local ecparams_file=crypto_data/ecparams.pem
+  # OpenSK AAGUID
+  local aaguid_file=crypto_data/aaguid.txt
+
+  set -e
+
+  # We need openssl command to continue
+  if [ ! -x "${openssl}" ]
   then
-    uuidgen > "${aaguid_file}"
+    echo "Missing openssl command. Try to specify its full path using OPENSSL environment variable."
+    exit 1
   fi
+
+  if [ ! -f "${ecparams_file}" ]
+  then
+    echo "Missing curve parameters. Has the PKI been generated?"
+    exit 1
+  fi
+
+  if [ ! -f "${aaguid_file}" ]
+  then
+    echo "Missing AAGUID file."
+    exit 1
+  fi
+
+  batch_id=$(uuidgen | tr -d '-')
+  aaguid=$(tr -d '-' < "${aaguid_file}")
+
+  # Attestation key pair and certificate that will be embedded into the
+  # firmware. The certificate will be signed by the Root CA.
+  local opensk_key=certs/${batch_id}.key
+  local opensk_cert_name=certs/${batch_id}
+
+  # x509v3 extension values are passed through environment variables.
+  export OPENSK_AAGUID="${aaguid}"
+  # Comma separated values of supported transport for the batch attestation certificate.
+  # 0=BTC, 1=BLE, 2=USB, 3=NFC
+  # Default to USB only
+  export OPENSK_TRANSPORT="${OPENSK_TRANSPORT:-2}"  # comma separated values. 1=BLE, 2=USB, 3=NFC
+
+  ask_for_password="$1"  
+  openssl_keypwd="-nodes"
+  openssl_batch="-batch"
+  if [ "${ask_for_password}" = "Y" ]
+  then
+    openssl_keypwd=""
+    openssl_batch=""
+  fi
+
+  # Generate certificate request for the current batch
+  "${openssl}" req \
+    -new \
+    -config "tools/openssl/opensk.conf" \
+    -keyout "crypto_data/${opensk_key}" \
+    -out "crypto_data/${opensk_cert_name}.csr" \
+    "${openssl_keypwd}" \
+    "${openssl_batch}" \
+    -newkey "ec:${ecparams_file}"
+  # Sign it using signing-CA and injecting the AAGUID as an extension
+  "${openssl}" ca \
+    -config "tools/openssl/signing-ca.conf" \
+    "${openssl_batch}" \
+    -in "crypto_data/${opensk_cert_name}.csr" \
+    -out "crypto_data/${opensk_cert_name}.pem" \
+    -extensions "fido_key_ext"
+
+  # Force symlink to the latest batch
+  ln -s -f "${opensk_cert_name}.pem" crypto_data/opensk_cert.pem
+  ln -s -f "${opensk_key}" crypto_data/opensk.key
 }
 
-generate_crypto_materials "$1"
+if [ "X${1}" != "X" ]
+then
+  ask_for_password=${2:-N}
+  generate_pki $1 $ask_for_password
+  if [ "$1" = "Y" -o ! -f "crypto_data/opensk.key" -o ! -f "crypto_data/opensk_cert.pem" ]
+  then
+    generate_new_batch $ask_for_password
+  fi
+fi
diff --git a/tools/openssl.ext b/tools/openssl.ext
deleted file mode 100644
index ac4f4ca8..00000000
--- a/tools/openssl.ext
+++ /dev/null
@@ -1 +0,0 @@
-basicConstraints=CA:FALSE
\ No newline at end of file
diff --git a/tools/openssl/opensk.conf b/tools/openssl/opensk.conf
new file mode 100644
index 00000000..717e9c42
--- /dev/null
+++ b/tools/openssl/opensk.conf
@@ -0,0 +1,26 @@
+oid_section = OIDS
+
+[ OIDS ]
+fido_attestation = 1.3.6.1.4.1.45724.2.1.1
+fido_aaguid = 1.3.6.1.4.1.45724.1.1.4
+
+[ req ]
+encrypt_key = no
+default_md = sha256
+utf8 = yes
+string_mask = utf8only
+prompt = no
+distinguished_name = fido_dn
+req_extensions = fido_reqext
+
+[ fido_dn ]
+countryName = "US"
+organizationName = "OpenSK"
+organizationalUnitName = "Authenticator Attestation"
+commonName = "OpenSK Hacker Edition"
+
+[ fido_reqext ]
+keyUsage                = critical,digitalSignature
+subjectKeyIdentifier    = hash
+fido_attestation        = ASN1:FORMAT:BITLIST,BITSTRING:${ENV::OPENSK_TRANSPORT}
+fido_aaguid             = ASN1:FORMAT:HEX,OCTETSTRING:${ENV::OPENSK_AAGUID}
diff --git a/tools/openssl/root-ca.conf b/tools/openssl/root-ca.conf
new file mode 100644
index 00000000..5aeb4062
--- /dev/null
+++ b/tools/openssl/root-ca.conf
@@ -0,0 +1,84 @@
+oid_section = OIDS
+
+[ default ]
+ca = root-ca
+dir = ./crypto_data
+
+[ req ]
+encrypt_key = yes
+default_md = sha256
+utf8 = yes
+string_mask = utf8only
+prompt = no
+distinguished_name = ca_dn
+req_extensions = ca_reqext
+
+[ OIDS ]
+fido_attestation = 1.3.6.1.4.1.45724.2.1.1
+fido_aaguid = 1.3.6.1.4.1.45724.1.1.4
+
+[ ca_dn ]
+countryName = "US"
+organizationName = "OpenSK"
+organizationalUnitName = "Authenticator Attestation"
+commonName = "OpenSK CA"
+
+[ ca_reqext ]
+keyUsage = critical,keyCertSign,cRLSign
+basicConstraints = critical,CA:true
+subjectKeyIdentifier = hash
+
+[ ca ]
+default_ca = root_ca
+
+[ root_ca ]
+certificate = $dir/ca/$ca.pem
+private_key = $dir/ca/$ca/private/$ca.key
+new_certs_dir = $dir/ca/$ca
+serial = $dir/ca/$ca/db/$ca.pem.srl
+crlnumber = $dir/ca/$ca/db/$ca.pem.srl
+database = $dir/ca/$ca/db/$ca.db
+unique_subject = no
+default_days = 36525
+default_md = sha256
+policy = match_pol
+email_in_dn = no
+preserve = no
+name_opt = ca_default
+cert_opt = ca_default
+copy_extensions = none
+x509_extensions = signing_ca_ext
+default_crl_days = 365
+crl_extensions = crl_ext
+
+[ match_pol ]
+countryName = match
+organizationName = match
+organizationalUnitName = match
+commonName = supplied
+
+[ any_pol ]
+countryName = optional
+stateOrProvinceName = optional
+localityName = optional
+organizationName = optional
+organizationalUnitName = optional
+commonName = optional
+emailAddress = optional
+
+[ root_ca_ext ]
+keyUsage = critical,keyCertSign,cRLSign
+basicConstraints = critical,CA:true
+subjectKeyIdentifier = hash
+authorityKeyIdentifier = keyid:always
+fido_attestation = ASN1:FORMAT:HEX,BITSTRING:00
+
+[ signing_ca_ext ]
+keyUsage = critical,keyCertSign,cRLSign
+basicConstraints = critical,CA:true,pathlen:0
+subjectKeyIdentifier = hash
+authorityKeyIdentifier = keyid:always
+
+[ crl_ext ]
+authorityKeyIdentifier = keyid:always
+
diff --git a/tools/openssl/signing-ca.conf b/tools/openssl/signing-ca.conf
new file mode 100644
index 00000000..c529c2c5
--- /dev/null
+++ b/tools/openssl/signing-ca.conf
@@ -0,0 +1,91 @@
+
+oid_section = OIDS
+
+[ default ]
+ca = signing-ca
+dir = ./crypto_data
+
+[ req ]
+default_bits = 4096
+encrypt_key = yes
+default_md = sha256
+utf8 = yes
+string_mask = utf8only
+prompt = no
+distinguished_name = ca_dn
+req_extensions = ca_reqext
+
+[ OIDS ]
+fido_attestation = 1.3.6.1.4.1.45724.2.1.1
+fido_aaguid = 1.3.6.1.4.1.45724.1.1.4
+
+[ ca_dn ]
+countryName = "US"
+organizationName = "OpenSK"
+organizationalUnitName = "Authenticator Attestation"
+commonName = "OpenSK Signing"
+
+[ ca_reqext ]
+keyUsage = critical,keyCertSign,cRLSign
+basicConstraints = critical,CA:true,pathlen:0
+subjectKeyIdentifier = hash
+
+[ ca ]
+default_ca = signing_ca
+
+[ signing_ca ]
+certificate = $dir/ca/$ca.pem
+private_key = $dir/ca/$ca/private/$ca.key
+new_certs_dir = $dir/ca/$ca
+serial = $dir/ca/$ca/db/$ca.pem.srl
+crlnumber = $dir/ca/$ca/db/$ca.pem.srl
+database = $dir/ca/$ca/db/$ca.db
+unique_subject = no
+default_days = 35064
+default_md = sha256
+policy = match_pol
+email_in_dn = no
+preserve = no
+name_opt = ca_default
+cert_opt = ca_default
+copy_extensions = copy
+x509_extensions = fido_key_ext
+default_crl_days = 7
+crl_extensions = crl_ext
+
+[ match_pol ]
+countryName = match
+organizationName = match
+organizationalUnitName = match
+commonName = supplied
+
+[ any_pol ]
+countryName = optional
+stateOrProvinceName = optional
+localityName = optional
+organizationName = optional
+organizationalUnitName = optional
+commonName = optional
+emailAddress = optional
+
+[ root_ca_ext ]
+keyUsage = critical,keyCertSign,cRLSign
+basicConstraints = critical,CA:true
+subjectKeyIdentifier = hash
+authorityKeyIdentifier = keyid:always
+
+[ signing_ca_ext ]
+keyUsage = critical,keyCertSign,cRLSign
+basicConstraints = critical,CA:true,pathlen:0
+subjectKeyIdentifier = hash
+authorityKeyIdentifier = keyid:always
+
+[ fido_key_ext ]
+keyUsage = critical,digitalSignature
+basicConstraints = CA:false
+subjectKeyIdentifier = hash
+authorityKeyIdentifier = keyid:always
+
+[ crl_ext ]
+authorityKeyIdentifier = keyid:always
+