Dangers of Single Sign On

I’ve always been a bit skeptical about single sign-on solutions, especially when they are the only thing standing between a would-be attacker and their goal. To me, the idea of a single sign-on solution linking a user to multiple subsystems represents a dangerous risk. A compromise at one point would propagate to other systems instantaneously. However, that doesn’t stop people from relying on them.

For example :

Winchester and Eastleigh Healthcare NHS Trust has deployed a single sign-on solution from Evidian to simplify access to key hospital applications, enabling 2,500 staff to better focus on the delivery of essential frontline healthcare services.
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With 1,700 clinicians at the Trust requiring access to up to 14 different healthcare applications on a day-to-day basis to carry out key services, the Enterprise SSO solution from leader in identity and access management Evidian enables clinicians to use all web-based services with a single user log-in and password.

A single sign-on solution for a hospital or clinic may certainly make things easier for staff— potentially decreasing mistakes and allowing things to flow more smoothly. However, the idea that one person’s password holds so much power is disturbing. I think perhaps it may be best to find some way to compromise. The inherent risk of a single sing-on solution can’t necessarily be overcome— accounts are linked, so access to one means access to all. However, I do believe the risk can be reduced through other methods. A multi-factor authentication system could help harden a single sign-on system like this. Especially when the private data of patients might be at stake.

Making things more convenient doesn’t always mean making them less secure.