diff --git a/src/boot-exit/README.md b/src/boot-exit/README.md
index d5c2b6c..cb41e4c 100755
--- a/src/boot-exit/README.md
+++ b/src/boot-exit/README.md
@@ -45,8 +45,8 @@
 ```sh
 cd disk-image
 # if packer (tool to build the disk) is not already installed
-wget https://releases.hashicorp.com/packer/1.4.3/packer_1.4.3_linux_amd64.zip
-unzip packer_1.4.3_linux_amd64.zip
+wget https://releases.hashicorp.com/packer/1.6.0/packer_1.6.0_linux_amd64.zip
+unzip packer_1.6.0_linux_amd64.zip
 
 # validate the packer script
 ./packer validate boot-exit/boot-exit.json
diff --git a/src/boot-exit/disk-image/boot-exit/boot-exit.json b/src/boot-exit/disk-image/boot-exit/boot-exit.json
index c82c2e7..1ad08df 100755
--- a/src/boot-exit/disk-image/boot-exit/boot-exit.json
+++ b/src/boot-exit/disk-image/boot-exit/boot-exit.json
@@ -32,8 +32,7 @@
             ],
             "headless": "{{ user `headless` }}",
             "http_directory": "shared",
-            "iso_checksum": "{{ user `iso_checksum` }}",
-            "iso_checksum_type": "{{ user `iso_checksum_type` }}",
+            "iso_checksum": "{{ user `iso_checksum_type` }}:{{ user `iso_checksum` }}",
             "iso_urls": [ "{{ user `iso_url` }}" ],
             "memory": "{{ user `vm_memory`}}",
             "output_directory": "boot-exit/{{ user `image_name` }}-image",
diff --git a/src/gapbs/README.md b/src/gapbs/README.md
index 12a3069..cdeb863 100644
--- a/src/gapbs/README.md
+++ b/src/gapbs/README.md
@@ -16,8 +16,8 @@
 
 ```sh
 cd disk-image/
-wget https://releases.hashicorp.com/packer/1.4.3/packer_1.4.3_linux_amd64.zip   # (if packer is not already installed)
-unzip packer_1.4.3_linux_amd64.zip # (if packer is not already installed)
+wget https://releases.hashicorp.com/packer/1.6.0/packer_1.6.0_linux_amd64.zip   # (if packer is not already installed)
+unzip packer_1.6.0_linux_amd64.zip # (if packer is not already installed)
 ./packer validate gapbs/gapbs.json
 ./packer build gapbs/gapbs.json
 ```
diff --git a/src/npb/README.md b/src/npb/README.md
index 441e1e6..294d265 100755
--- a/src/npb/README.md
+++ b/src/npb/README.md
@@ -63,8 +63,8 @@
 ```sh
 cd disk-image
 # if packer is not already installed
-wget https://releases.hashicorp.com/packer/1.4.3/packer_1.4.3_linux_amd64.zip
-unzip packer_1.4.3_linux_amd64.zip
+wget https://releases.hashicorp.com/packer/1.6.0/packer_1.6.0_linux_amd64.zip
+unzip packer_1.6.0_linux_amd64.zip
 
 # validate the packer script
 ./packer validate npb/npb.json
diff --git a/src/npb/disk-image/npb/npb.json b/src/npb/disk-image/npb/npb.json
index 1f8df4c..73e62d6 100755
--- a/src/npb/disk-image/npb/npb.json
+++ b/src/npb/disk-image/npb/npb.json
@@ -32,8 +32,7 @@
             ],
             "headless": "{{ user `headless` }}",
             "http_directory": "shared/",
-            "iso_checksum": "{{ user `iso_checksum` }}",
-            "iso_checksum_type": "{{ user `iso_checksum_type` }}",
+            "iso_checksum": "{{ user `iso_checksum_type` }}:{{ user `iso_checksum` }}",
             "iso_urls": [ "{{ user `iso_url` }}" ],
             "memory": "{{ user `vm_memory`}}",
             "output_directory": "npb/{{ user `image_name` }}-image",
diff --git a/src/parsec/README.md b/src/parsec/README.md
index b3a9e1a..17bdc62 100644
--- a/src/parsec/README.md
+++ b/src/parsec/README.md
@@ -46,8 +46,8 @@
 
 ```sh
 cd disk-image
-wget https://releases.hashicorp.com/packer/1.4.3/packer_1.4.3_linux_amd64.zip
-unzip packer_1.4.3_linux_amd64.zip
+wget https://releases.hashicorp.com/packer/1.6.0/packer_1.6.0_linux_amd64.zip
+unzip packer_1.6.0_linux_amd64.zip
 ```
 
 In order to build the disk-image first the script needs to be validated. Run the following command to validate `disk-image/parsec/parsec.json`.
diff --git a/src/parsec/disk-image/parsec/parsec.json b/src/parsec/disk-image/parsec/parsec.json
index 1d3b0e6..a4270d5 100644
--- a/src/parsec/disk-image/parsec/parsec.json
+++ b/src/parsec/disk-image/parsec/parsec.json
@@ -32,8 +32,7 @@
             ],
             "headless": "{{ user `headless` }}",
             "http_directory": "shared/",
-            "iso_checksum": "{{ user `iso_checksum` }}",
-            "iso_checksum_type": "{{ user `iso_checksum_type` }}",
+            "iso_checksum": "{{ user `iso_checksum_type` }}:{{ user `iso_checksum` }}",
             "iso_urls": [ "{{ user `iso_url` }}" ],
             "memory": "{{ user `vm_memory`}}",
             "output_directory": "parsec/{{ user `image_name` }}-image",
diff --git a/src/spec-2006/README.md b/src/spec-2006/README.md
index 3122f90..91ac058 100644
--- a/src/spec-2006/README.md
+++ b/src/spec-2006/README.md
@@ -52,8 +52,8 @@
 
 ```sh
 cd disk-image
-wget https://releases.hashicorp.com/packer/1.4.3/packer_1.4.3_linux_amd64.zip #(download the packer binary)
-unzip packer_1.4.3_linux_amd64.zip
+wget https://releases.hashicorp.com/packer/1.6.0/packer_1.6.0_linux_amd64.zip #(download the packer binary)
+unzip packer_1.6.0_linux_amd64.zip
 ./packer validate spec-2006/spec-2006.json #validate the Packer script
 ./packer build spec-2006/spec-2006.json
 ```
diff --git a/src/spec-2006/disk-image/spec-2006/spec-2006.json b/src/spec-2006/disk-image/spec-2006/spec-2006.json
index 1edfc3d..1e2fb7b 100644
--- a/src/spec-2006/disk-image/spec-2006/spec-2006.json
+++ b/src/spec-2006/disk-image/spec-2006/spec-2006.json
@@ -32,8 +32,7 @@
             ],
             "headless": "{{ user `headless` }}",
             "http_directory": "shared",
-            "iso_checksum": "{{ user `iso_checksum` }}",
-            "iso_checksum_type": "{{ user `iso_checksum_type` }}",
+            "iso_checksum": "{{ user `iso_checksum_type` }}:{{ user `iso_checksum` }}",
             "iso_urls": [ "{{ user `iso_url` }}" ],
             "memory": "{{ user `vm_memory`}}",
             "output_directory": "spec-2006/{{ user `image_name` }}-image",
diff --git a/src/spec-2017/README.md b/src/spec-2017/README.md
index 32d53bf..b05f215 100644
--- a/src/spec-2017/README.md
+++ b/src/spec-2017/README.md
@@ -53,8 +53,8 @@
 
 ```sh
 cd disk-image
-wget https://releases.hashicorp.com/packer/1.4.3/packer_1.4.3_linux_amd64.zip # download the packer binary
-unzip packer_1.4.3_linux_amd64.zip
+wget https://releases.hashicorp.com/packer/1.6.0/packer_1.6.0_linux_amd64.zip # download the packer binary
+unzip packer_1.6.0_linux_amd64.zip
 ./packer validate spec-2017/spec-2017.json # validate the Packer script
 ./packer build spec-2017/spec-2017.json
 ```
diff --git a/src/spec-2017/disk-image/spec-2017/spec-2017.json b/src/spec-2017/disk-image/spec-2017/spec-2017.json
index b750f14..007dea5 100644
--- a/src/spec-2017/disk-image/spec-2017/spec-2017.json
+++ b/src/spec-2017/disk-image/spec-2017/spec-2017.json
@@ -32,8 +32,7 @@
             ],
             "headless": "{{ user `headless` }}",
             "http_directory": "shared",
-            "iso_checksum": "{{ user `iso_checksum` }}",
-            "iso_checksum_type": "{{ user `iso_checksum_type` }}",
+            "iso_checksum": "{{ user `iso_checksum_type` }}:{{ user `iso_checksum` }}",
             "iso_urls": [ "{{ user `iso_url` }}" ],
             "memory": "{{ user `vm_memory`}}",
             "output_directory": "spec-2017/{{ user `image_name` }}-image",