Arclight: /* Message Transaction Flow */

2011-11-26T07:56:15Z

Message Transaction Flow

← Older revision		Revision as of 00:56, 26 November 2011
Line 7:		Line 7:
	IDs and a message with the card serial number. Copies of the node ID		IDs and a message with the card serial number. Copies of the node ID
	and (optional) destination are contained in a clear-text header. The		and (optional) destination are contained in a clear-text header. The
	payload is encrypted using AES128~~/256~~ and a key unique to that reader.		payload is encrypted using AES128 and a key unique to that reader.

	2. If the "card" is a smart phone with NFC, then the payload also		2. If the "card" is a smart phone with NFC, then the payload also
	contains an encrypted message sent from the phone during the NFC		contains an encrypted message sent from the phone during the NFC
	exchange, which has a time stamp and a (random) serial number as well.		exchange, which has a time stamp and a (random) serial number as well.

	3. An 'ACK' message is sent to the reader once the message has been		3. An 'ACK' message is sent to the reader once the message has been
	received by the server.		received by the server.
	4. Once received, the ~~messagr~~ payload is decrypted using a unique key
			4. Once received, the message payload is decrypted using a unique key
	for that reader, loaded up from the data base.		for that reader, loaded up from the data base.
	If the message:
			If the message:

	a. Decrypts with the correct reader's key and		a. Decrypts with the correct reader's key and
	b. the access rules allow access and		b. the access rules allow access and
	c. the message in the payload from the phone also decrypts using		c. the message in the payload from the phone also decrypts using a key unique to that phone/user then"
	a key unique to that phone/user then"
	5. A message to the phone with an acknowledgment and any message we		5. A message to the phone with an acknowledgment and any message we
	wish to pass to the user's screen is created and encrypted and added		wish to pass to the user's screen is created and encrypted and added
	to the payload to be sent to the reader.		to the payload to be sent to the reader.

	6. The response message is sent to the reader and decrypted. The		6. The response message is sent to the reader and decrypted. The
	command contained in the response is followed and the user is		command contained in the response is followed and the user is

	a. Allowed access or		a. Allowed access or
	b. Denied access		b. Denied access

Arclight: Created page with "===Message Transaction Flow=== 1. When a 13.56Mhz token is read, the reader (or more likely the microcontroller attached to it) generates a time-stamped and (random) serialize..."

2011-11-26T07:54:30Z

Created page with "===Message Transaction Flow=== 1. When a 13.56Mhz token is read, the reader (or more likely the microcontroller attached to it) generates a time-stamped and (random) serialize..."

New page

===Message Transaction Flow===

1. When a 13.56Mhz token is read, the reader (or more likely the
microcontroller attached to it) generates a time-stamped and (random)
serialized packet. The packet format contains the node and door/reader
IDs and a message with the card serial number. Copies of the node ID
and (optional) destination are contained in a clear-text header. The
payload is encrypted using AES128/256 and a key unique to that reader.

2. If the "card" is a smart phone with NFC, then the payload also
contains an encrypted message sent from the phone during the NFC
exchange, which has a time stamp and a (random) serial number as well.
3. An 'ACK' message is sent to the reader once the message has been
received by the server.
4. Once received, the messagr payload is decrypted using a unique key
for that reader, loaded up from the data base.
If the message:
a. Decrypts with the correct reader's key and
b. the access rules allow access and
c. the message in the payload from the phone also decrypts using
a key unique to that phone/user then"
5. A message to the phone with an acknowledgment and any message we
wish to pass to the user's screen is created and encrypted and added
to the payload to be sent to the reader.
6. The response message is sent to the reader and decrypted. The
command contained in the response is followed and the user is
a. Allowed access or
b. Denied access
c. Optionally passed an encrypted message back from the payload.

The minimum payload appears to be 84-100bytes, more if we make the
messages longer. This would also fit into a 160-byte SMS message,
which could make GSM access easier.

Example Message Flow - Revision history

Arclight: /* Message Transaction Flow */

Arclight: Created page with "===Message Transaction Flow=== 1. When a 13.56Mhz token is read, the reader (or more likely the microcontroller attached to it) generates a time-stamped and (random) serialize..."