Backdoors: When Good Intentions Go Bad

Whenever bad things happen where perpetrators had used encryption, the topic of government access to encrypted data turns into a heated debate. 

The latest example comes on the heels of the horrible terrorist attack near the Palace of Westminster in London, where there was evidence that the perpetrator had used WhatsApp, an encrypted messaging program, possibly to communicate with accomplices. UK Home Secretary Amber Rudd raised the government access issue, saying "… on this situation we need to make sure that our intelligence services have the ability to get into situations like encrypted WhatsApp." 

In the US, this was reminiscent of an earlier high-profile attack in San Bernardino, California, where one of the shooters possessed an iPhone with encrypted data. In the aftermath, FBI Director James Comey lamented, "if the challenges of real-time interception threaten to leave us in the dark, encryption threatens to lead all of us to a very dark place." These leaders share a clear message: the technology community should be designing products that make encrypted communications accessible to the government when necessary.

Legal Yet Vulnerable
What could possibly be wrong with helping law enforcement use legal means to catch terrorists? If technology can hide communications, can't technology be used in a legal and safe way to reveal critical information when people's lives are at stake?

Unfortunately, the answer is that these requests for access to encrypted information creates "backdoors" that can make all citizens vulnerable to attack. A backdoor in security is a way for an entity (like the government) to access encrypted information. Protecting data using encryption involves creating an encryption key, which is the equivalent of the key to the lock on the front door of one's house. The idea of a backdoor is to provide another key so that law enforcement can enter the house if necessary. Just as the backdoor to the house will open for anyone – friend or foe – with the correct key, an encryption backdoor can make users' information accessible for both good and bad purposes.

Here’s why backdoors are such a bad idea:

Bad guys can easily circumvent backdoors. Really good encryption technology is available in the public domain. It can be easily downloaded over the Internet, and it's widely available around the world. If a government were to mandate that an encrypted application have a backdoor, the bad guys would simply choose to use one of the many widely available alternatives without a backdoor. It wouldn't be any easier to decode bad guys' communications than it is now. 

Good guys will be vulnerable. That's because hackers will ultimately breach backdoors. Mandated backdoors will make law-abiding individuals less secure because the potential for hackers to get the keys to these backdoors will compromise everyone's information. These risks are not just theoretical; backdoors have been breached many times. For example:

Technology's Not the Answer
Can't this problem be solved with more innovative technology or better access procedures? Some of the world's best computer security experts who have been studying the problem for the past two decades don't think so. They published a thought-provoking analysis of the topic in an MIT paper titled, "Keys Under Doormats: Mandating insecurity by requiring government access to all data and communications."   

The experts noted that "the damage that could be caused by law enforcement exceptional access requirements would be even greater today than it would have been 20 years ago." After examining both the technology and policy implications, they conclude "the prospect of globally deployed exceptional access systems raises difficult problems about how such an environment would be governed and how to ensure that such systems would respect human rights and the rule of law."

Since the invention of encryption decades ago, various proposals have been made to limit the technology so that it's accessible to law enforcement. And each time the proposals have failed for the same reason: government-mandated backdoors lead to a world where law enforcement can't catch any more bad guys, and the good guys are more vulnerable. The same backdoor designed for law enforcement can be and will be exploited by others with sinister motives.

[Check out the two-day Dark Reading Cybersecurity Crash Course at Interop ITX, May 15 & 16, where Dark Reading editors and some of the industry's top cybersecurity experts will share the latest data security trends and best practices.]

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