diff --git a/tools/cert_create/Makefile b/tools/cert_create/Makefile
index eff929e..19f736f 100644
--- a/tools/cert_create/Makefile
+++ b/tools/cert_create/Makefile
@@ -27,6 +27,8 @@
 # Chain of trust.
 ifeq (${COT},tbbr)
   include src/tbbr/tbbr.mk
+else ifeq (${COT},dualroot)
+  include src/dualroot/cot.mk
 else
   $(error Unknown chain of trust ${COT})
 endif
diff --git a/tools/cert_create/include/dualroot/cot.h b/tools/cert_create/include/dualroot/cot.h
new file mode 100644
index 0000000..5701206
--- /dev/null
+++ b/tools/cert_create/include/dualroot/cot.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef DUALROOT_COT_H
+#define DUALROOT_COT_H
+
+/* Certificates. */
+enum {
+	/* Certificates owned by the silicon provider. */
+	TRUSTED_BOOT_FW_CERT,
+	TRUSTED_KEY_CERT,
+	SCP_FW_KEY_CERT,
+	SCP_FW_CONTENT_CERT,
+	SOC_FW_KEY_CERT,
+	SOC_FW_CONTENT_CERT,
+	TRUSTED_OS_FW_KEY_CERT,
+	TRUSTED_OS_FW_CONTENT_CERT,
+	FWU_CERT,
+
+	/* Certificates owned by the platform owner. */
+	NON_TRUSTED_FW_CONTENT_CERT,
+};
+
+/* Certificate extensions. */
+enum {
+	/* Extensions used in certificates owned by the silicon provider. */
+	TRUSTED_FW_NVCOUNTER_EXT,
+	TRUSTED_BOOT_FW_HASH_EXT,
+	TRUSTED_BOOT_FW_CONFIG_HASH_EXT,
+	HW_CONFIG_HASH_EXT,
+	TRUSTED_WORLD_PK_EXT,
+	SCP_FW_CONTENT_CERT_PK_EXT,
+	SCP_FW_HASH_EXT,
+	SOC_FW_CONTENT_CERT_PK_EXT,
+	SOC_AP_FW_HASH_EXT,
+	SOC_FW_CONFIG_HASH_EXT,
+	TRUSTED_OS_FW_CONTENT_CERT_PK_EXT,
+	TRUSTED_OS_FW_HASH_EXT,
+	TRUSTED_OS_FW_EXTRA1_HASH_EXT,
+	TRUSTED_OS_FW_EXTRA2_HASH_EXT,
+	TRUSTED_OS_FW_CONFIG_HASH_EXT,
+	SCP_FWU_CFG_HASH_EXT,
+	AP_FWU_CFG_HASH_EXT,
+	FWU_HASH_EXT,
+
+	/* Extensions used in certificates owned by the platform owner. */
+	PROT_PK_EXT,
+	NON_TRUSTED_FW_NVCOUNTER_EXT,
+	NON_TRUSTED_FW_CONTENT_CERT_PK_EXT,
+	NON_TRUSTED_WORLD_BOOTLOADER_HASH_EXT,
+	NON_TRUSTED_FW_CONFIG_HASH_EXT,
+};
+
+/* Keys. */
+enum {
+	/* Keys owned by the silicon provider. */
+	ROT_KEY,
+	TRUSTED_WORLD_KEY,
+	SCP_FW_CONTENT_CERT_KEY,
+	SOC_FW_CONTENT_CERT_KEY,
+	TRUSTED_OS_FW_CONTENT_CERT_KEY,
+
+	/* Keys owned by the platform owner. */
+	PROT_KEY,
+};
+
+#endif /* DUALROOT_COT_H */
diff --git a/tools/cert_create/src/dualroot/cot.c b/tools/cert_create/src/dualroot/cot.c
new file mode 100644
index 0000000..8117ffc
--- /dev/null
+++ b/tools/cert_create/src/dualroot/cot.c
@@ -0,0 +1,453 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <dualroot_oid.h>
+
+#include "cert.h"
+#include "ext.h"
+#include "key.h"
+
+#include "dualroot/cot.h"
+
+/*
+ * Certificates used in the chain of trust.
+ *
+ * All certificates are self-signed so the issuer certificate field points to
+ * itself.
+ */
+static cert_t cot_certs[] = {
+	[TRUSTED_BOOT_FW_CERT] = {
+		.id = TRUSTED_BOOT_FW_CERT,
+		.opt = "tb-fw-cert",
+		.help_msg = "Trusted Boot FW Certificate (output file)",
+		.cn = "Trusted Boot FW Certificate",
+		.key = ROT_KEY,
+		.issuer = TRUSTED_BOOT_FW_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			TRUSTED_BOOT_FW_HASH_EXT,
+			TRUSTED_BOOT_FW_CONFIG_HASH_EXT,
+			HW_CONFIG_HASH_EXT
+		},
+		.num_ext = 4
+	},
+
+	[TRUSTED_KEY_CERT] = {
+		.id = TRUSTED_KEY_CERT,
+		.opt = "trusted-key-cert",
+		.help_msg = "Trusted Key Certificate (output file)",
+		.cn = "Trusted Key Certificate",
+		.key = ROT_KEY,
+		.issuer = TRUSTED_KEY_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			TRUSTED_WORLD_PK_EXT,
+		},
+		.num_ext = 2
+	},
+
+	[SCP_FW_KEY_CERT] = {
+		.id = SCP_FW_KEY_CERT,
+		.opt = "scp-fw-key-cert",
+		.help_msg = "SCP Firmware Key Certificate (output file)",
+		.cn = "SCP Firmware Key Certificate",
+		.key = TRUSTED_WORLD_KEY,
+		.issuer = SCP_FW_KEY_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			SCP_FW_CONTENT_CERT_PK_EXT
+		},
+		.num_ext = 2
+	},
+
+	[SCP_FW_CONTENT_CERT] = {
+		.id = SCP_FW_CONTENT_CERT,
+		.opt = "scp-fw-cert",
+		.help_msg = "SCP Firmware Content Certificate (output file)",
+		.cn = "SCP Firmware Content Certificate",
+		.key = SCP_FW_CONTENT_CERT_KEY,
+		.issuer = SCP_FW_CONTENT_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			SCP_FW_HASH_EXT
+		},
+		.num_ext = 2
+	},
+
+	[SOC_FW_KEY_CERT] = {
+		.id = SOC_FW_KEY_CERT,
+		.opt = "soc-fw-key-cert",
+		.help_msg = "SoC Firmware Key Certificate (output file)",
+		.cn = "SoC Firmware Key Certificate",
+		.key = TRUSTED_WORLD_KEY,
+		.issuer = SOC_FW_KEY_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			SOC_FW_CONTENT_CERT_PK_EXT
+		},
+		.num_ext = 2
+	},
+
+	[SOC_FW_CONTENT_CERT] = {
+		.id = SOC_FW_CONTENT_CERT,
+		.opt = "soc-fw-cert",
+		.help_msg = "SoC Firmware Content Certificate (output file)",
+		.cn = "SoC Firmware Content Certificate",
+		.key = SOC_FW_CONTENT_CERT_KEY,
+		.issuer = SOC_FW_CONTENT_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			SOC_AP_FW_HASH_EXT,
+			SOC_FW_CONFIG_HASH_EXT,
+		},
+		.num_ext = 3
+	},
+
+	[TRUSTED_OS_FW_KEY_CERT] = {
+		.id = TRUSTED_OS_FW_KEY_CERT,
+		.opt = "tos-fw-key-cert",
+		.help_msg = "Trusted OS Firmware Key Certificate (output file)",
+		.cn = "Trusted OS Firmware Key Certificate",
+		.key = TRUSTED_WORLD_KEY,
+		.issuer = TRUSTED_OS_FW_KEY_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			TRUSTED_OS_FW_CONTENT_CERT_PK_EXT
+		},
+		.num_ext = 2
+	},
+
+	[TRUSTED_OS_FW_CONTENT_CERT] = {
+		.id = TRUSTED_OS_FW_CONTENT_CERT,
+		.opt = "tos-fw-cert",
+		.help_msg = "Trusted OS Firmware Content Certificate (output file)",
+		.cn = "Trusted OS Firmware Content Certificate",
+		.key = TRUSTED_OS_FW_CONTENT_CERT_KEY,
+		.issuer = TRUSTED_OS_FW_CONTENT_CERT,
+		.ext = {
+			TRUSTED_FW_NVCOUNTER_EXT,
+			TRUSTED_OS_FW_HASH_EXT,
+			TRUSTED_OS_FW_EXTRA1_HASH_EXT,
+			TRUSTED_OS_FW_EXTRA2_HASH_EXT,
+			TRUSTED_OS_FW_CONFIG_HASH_EXT,
+		},
+		.num_ext = 5
+	},
+
+	[FWU_CERT] = {
+		.id = FWU_CERT,
+		.opt = "fwu-cert",
+		.help_msg = "Firmware Update Certificate (output file)",
+		.cn = "Firmware Update Certificate",
+		.key = ROT_KEY,
+		.issuer = FWU_CERT,
+		.ext = {
+			SCP_FWU_CFG_HASH_EXT,
+			AP_FWU_CFG_HASH_EXT,
+			FWU_HASH_EXT
+		},
+		.num_ext = 3
+	},
+
+	[NON_TRUSTED_FW_CONTENT_CERT] = {
+		.id = NON_TRUSTED_FW_CONTENT_CERT,
+		.opt = "nt-fw-cert",
+		.help_msg = "Non-Trusted Firmware Content Certificate (output file)",
+		.cn = "Non-Trusted Firmware Content Certificate",
+		.key = PROT_KEY,
+		.issuer = NON_TRUSTED_FW_CONTENT_CERT,
+		.ext = {
+			NON_TRUSTED_FW_NVCOUNTER_EXT,
+			NON_TRUSTED_WORLD_BOOTLOADER_HASH_EXT,
+			NON_TRUSTED_FW_CONFIG_HASH_EXT,
+			PROT_PK_EXT,
+		},
+		.num_ext = 4
+	},
+};
+
+REGISTER_COT(cot_certs);
+
+
+/* Certificate extensions. */
+static ext_t cot_ext[] = {
+	[TRUSTED_FW_NVCOUNTER_EXT] = {
+		.oid = TRUSTED_FW_NVCOUNTER_OID,
+		.opt = "tfw-nvctr",
+		.help_msg = "Trusted Firmware Non-Volatile counter value",
+		.sn = "TrustedWorldNVCounter",
+		.ln = "Trusted World Non-Volatile counter",
+		.asn1_type = V_ASN1_INTEGER,
+		.type = EXT_TYPE_NVCOUNTER,
+		.attr.nvctr_type = NVCTR_TYPE_TFW
+	},
+
+	[TRUSTED_BOOT_FW_HASH_EXT] = {
+		.oid = TRUSTED_BOOT_FW_HASH_OID,
+		.opt = "tb-fw",
+		.help_msg = "Trusted Boot Firmware image file",
+		.sn = "TrustedBootFirmwareHash",
+		.ln = "Trusted Boot Firmware hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH
+	},
+
+	[TRUSTED_BOOT_FW_CONFIG_HASH_EXT] = {
+		.oid = TRUSTED_BOOT_FW_CONFIG_HASH_OID,
+		.opt = "tb-fw-config",
+		.help_msg = "Trusted Boot Firmware Config file",
+		.sn = "TrustedBootFirmwareConfigHash",
+		.ln = "Trusted Boot Firmware Config hash",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[HW_CONFIG_HASH_EXT] = {
+		.oid = HW_CONFIG_HASH_OID,
+		.opt = "hw-config",
+		.help_msg = "HW Config file",
+		.sn = "HWConfigHash",
+		.ln = "HW Config hash",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[TRUSTED_WORLD_PK_EXT] = {
+		.oid = TRUSTED_WORLD_PK_OID,
+		.sn = "TrustedWorldPublicKey",
+		.ln = "Trusted World Public Key",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_PKEY,
+		.attr.key = TRUSTED_WORLD_KEY
+	},
+
+	[SCP_FW_CONTENT_CERT_PK_EXT] = {
+		.oid = SCP_FW_CONTENT_CERT_PK_OID,
+		.sn = "SCPFirmwareContentCertPK",
+		.ln = "SCP Firmware content certificate public key",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_PKEY,
+		.attr.key = SCP_FW_CONTENT_CERT_KEY
+	},
+
+	[SCP_FW_HASH_EXT] = {
+		.oid = SCP_FW_HASH_OID,
+		.opt = "scp-fw",
+		.help_msg = "SCP Firmware image file",
+		.sn = "SCPFirmwareHash",
+		.ln = "SCP Firmware hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH
+	},
+
+	[SOC_FW_CONTENT_CERT_PK_EXT] = {
+		.oid = SOC_FW_CONTENT_CERT_PK_OID,
+		.sn = "SoCFirmwareContentCertPK",
+		.ln = "SoC Firmware content certificate public key",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_PKEY,
+		.attr.key = SOC_FW_CONTENT_CERT_KEY
+	},
+
+	[SOC_AP_FW_HASH_EXT] = {
+		.oid = SOC_AP_FW_HASH_OID,
+		.opt = "soc-fw",
+		.help_msg = "SoC AP Firmware image file",
+		.sn = "SoCAPFirmwareHash",
+		.ln = "SoC AP Firmware hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH
+	},
+
+	[SOC_FW_CONFIG_HASH_EXT] = {
+		.oid = SOC_FW_CONFIG_HASH_OID,
+		.opt = "soc-fw-config",
+		.help_msg = "SoC Firmware Config file",
+		.sn = "SocFirmwareConfigHash",
+		.ln = "SoC Firmware Config hash",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[TRUSTED_OS_FW_CONTENT_CERT_PK_EXT] = {
+		.oid = TRUSTED_OS_FW_CONTENT_CERT_PK_OID,
+		.sn = "TrustedOSFirmwareContentCertPK",
+		.ln = "Trusted OS Firmware content certificate public key",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_PKEY,
+		.attr.key = TRUSTED_OS_FW_CONTENT_CERT_KEY
+	},
+
+	[TRUSTED_OS_FW_HASH_EXT] = {
+		.oid = TRUSTED_OS_FW_HASH_OID,
+		.opt = "tos-fw",
+		.help_msg = "Trusted OS image file",
+		.sn = "TrustedOSHash",
+		.ln = "Trusted OS hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH
+	},
+
+	[TRUSTED_OS_FW_EXTRA1_HASH_EXT] = {
+		.oid = TRUSTED_OS_FW_EXTRA1_HASH_OID,
+		.opt = "tos-fw-extra1",
+		.help_msg = "Trusted OS Extra1 image file",
+		.sn = "TrustedOSExtra1Hash",
+		.ln = "Trusted OS Extra1 hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[TRUSTED_OS_FW_EXTRA2_HASH_EXT] = {
+		.oid = TRUSTED_OS_FW_EXTRA2_HASH_OID,
+		.opt = "tos-fw-extra2",
+		.help_msg = "Trusted OS Extra2 image file",
+		.sn = "TrustedOSExtra2Hash",
+		.ln = "Trusted OS Extra2 hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[TRUSTED_OS_FW_CONFIG_HASH_EXT] = {
+		.oid = TRUSTED_OS_FW_CONFIG_HASH_OID,
+		.opt = "tos-fw-config",
+		.help_msg = "Trusted OS Firmware Config file",
+		.sn = "TrustedOSFirmwareConfigHash",
+		.ln = "Trusted OS Firmware Config hash",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[SCP_FWU_CFG_HASH_EXT] = {
+		.oid = SCP_FWU_CFG_HASH_OID,
+		.opt = "scp-fwu-cfg",
+		.help_msg = "SCP Firmware Update Config image file",
+		.sn = "SCPFWUpdateConfig",
+		.ln = "SCP Firmware Update Config hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[AP_FWU_CFG_HASH_EXT] = {
+		.oid = AP_FWU_CFG_HASH_OID,
+		.opt = "ap-fwu-cfg",
+		.help_msg = "AP Firmware Update Config image file",
+		.sn = "APFWUpdateConfig",
+		.ln = "AP Firmware Update Config hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[FWU_HASH_EXT] = {
+		.oid = FWU_HASH_OID,
+		.opt = "fwu",
+		.help_msg = "Firmware Updater image file",
+		.sn = "FWUpdaterHash",
+		.ln = "Firmware Updater hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+
+	[PROT_PK_EXT] = {
+		.oid = PROT_PK_OID,
+		.sn = "PlatformRoTKey",
+		.ln = "Platform Root of Trust Public Key",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_PKEY,
+		.attr.key = PROT_KEY
+	},
+
+	[NON_TRUSTED_FW_NVCOUNTER_EXT] = {
+		.oid = NON_TRUSTED_FW_NVCOUNTER_OID,
+		.opt = "ntfw-nvctr",
+		.help_msg = "Non-Trusted Firmware Non-Volatile counter value",
+		.sn = "NormalWorldNVCounter",
+		.ln = "Non-Trusted Firmware Non-Volatile counter",
+		.asn1_type = V_ASN1_INTEGER,
+		.type = EXT_TYPE_NVCOUNTER,
+		.attr.nvctr_type = NVCTR_TYPE_NTFW
+	},
+
+	[NON_TRUSTED_WORLD_BOOTLOADER_HASH_EXT] = {
+		.oid = NON_TRUSTED_WORLD_BOOTLOADER_HASH_OID,
+		.opt = "nt-fw",
+		.help_msg = "Non-Trusted World Bootloader image file",
+		.sn = "NonTrustedWorldBootloaderHash",
+		.ln = "Non-Trusted World hash (SHA256)",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH
+	},
+
+	[NON_TRUSTED_FW_CONFIG_HASH_EXT] = {
+		.oid = NON_TRUSTED_FW_CONFIG_HASH_OID,
+		.opt = "nt-fw-config",
+		.help_msg = "Non Trusted OS Firmware Config file",
+		.sn = "NonTrustedOSFirmwareConfigHash",
+		.ln = "Non-Trusted OS Firmware Config hash",
+		.asn1_type = V_ASN1_OCTET_STRING,
+		.type = EXT_TYPE_HASH,
+		.optional = 1
+	},
+};
+
+REGISTER_EXTENSIONS(cot_ext);
+
+
+/* Keys used to establish the chain of trust. */
+static key_t cot_keys[] = {
+	[ROT_KEY] = {
+		.id = ROT_KEY,
+		.opt = "rot-key",
+		.help_msg = "Root Of Trust key (input/output file)",
+		.desc = "Root Of Trust key"
+	},
+
+	[TRUSTED_WORLD_KEY] = {
+		.id = TRUSTED_WORLD_KEY,
+		.opt = "trusted-world-key",
+		.help_msg = "Trusted World key (input/output file)",
+		.desc = "Trusted World key"
+	},
+
+	[SCP_FW_CONTENT_CERT_KEY] = {
+		.id = SCP_FW_CONTENT_CERT_KEY,
+		.opt = "scp-fw-key",
+		.help_msg = "SCP Firmware Content Certificate key (input/output file)",
+		.desc = "SCP Firmware Content Certificate key"
+	},
+
+	[SOC_FW_CONTENT_CERT_KEY] = {
+		.id = SOC_FW_CONTENT_CERT_KEY,
+		.opt = "soc-fw-key",
+		.help_msg = "SoC Firmware Content Certificate key (input/output file)",
+		.desc = "SoC Firmware Content Certificate key"
+	},
+
+	[TRUSTED_OS_FW_CONTENT_CERT_KEY] = {
+		.id = TRUSTED_OS_FW_CONTENT_CERT_KEY,
+		.opt = "tos-fw-key",
+		.help_msg = "Trusted OS Firmware Content Certificate key (input/output file)",
+		.desc = "Trusted OS Firmware Content Certificate key"
+	},
+
+	[PROT_KEY] = {
+		.id = PROT_KEY,
+		.opt = "prot-key",
+		.help_msg = "Platform Root of Trust key",
+		.desc = "Platform Root of Trust key"
+	},
+};
+
+REGISTER_KEYS(cot_keys);
diff --git a/tools/cert_create/src/dualroot/cot.mk b/tools/cert_create/src/dualroot/cot.mk
new file mode 100644
index 0000000..a572484
--- /dev/null
+++ b/tools/cert_create/src/dualroot/cot.mk
@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+PLAT_MSG		:=	Dual root of trust
+PLAT_INCLUDE		:=	../../include/tools_share
+
+OBJECTS += src/dualroot/cot.o