The importance of 'whole journey' email encryption
Leave no weak spots
It is very rare for an organisation to mandate less security in its IT systems. In fact, the relentless march of new threats places pressure on us all to increase our levels of security, to ensure we can match new and emerging attacks.
Email is one of the most potent business tools that we have, but also one of the most vulnerable systems for attack.
The volume of organisational "smarts" that can travel out of the virtual front door (or the back door from rogue inside abuse) via email can be staggering. Quotes, legal information, contracts, customer data and just about every type of document you can think of will be transported via email.
After all, traditional "snail mail" is all but dead for day to day commercial communications.
Securing email systems must be at the top of any corporate security expert's to-do list, but as with most IT problems there are many different approaches you can take.
One interesting debate is that of precisely when and where to encrypt your email traffic. Is it at the client or is it at the gateway prior to sending to the recipient? Or maybe the encryption is only from the gateway to the recipient client?
From gateway to gateway
The majority of organisations are happy with the placing of an email gateway of some description that encrypts messages as they leave the corporate perimeter. These gateways are often appliances that process emails as they leave and enter the organisation as well as providing anti-malware support.
The problem with email gateway encryption is that emails are not encrypted until they get to the gateway. In other words, the gateway does not protect internal email or email that is travelling from the internal network towards the gateway. These emails will travel around the internal organisation network unencrypted and in plain text, vulnerable to prying malware or internal monitoring and snooping devices.
Some organisations may be comfortable with this, but those needing a higher level of email security need to look a bit deeper.
Well, malicious insiders will often make a point of going after internal email traffic as this is often seen as a soft target. In a large organisation thousands of plain text emails can be moving around the organisation at any moment in time. These can be accessible to anyone motivated enough to run a sniffing device on the network, and certainly any prying email systems administrator would have unfettered access. Even if an email is worthless outside an organisation, internally it may be priceless and cause significant controversy if its contents were revealed. Examples would include emails discussing redundancies and pay rises for a start.
Most vulnerable to outside interference would be the ubiquitous mobile user with a handheld device. Tour any financial centre and see the thousands of city whizz-kids passing data around in email form, with goodness knows what data being passed in plain text. Unless emails are secured before they leave a handheld device, organisations leave a big gap in their security measures here.
By focusing solely on email gateway to gateway encryption, users risk exposing themselves to unnecessary risk of email intrusion.