Data security

Why your exams are secure with easyRadiology

easyRadiology uses military grade encryption to protect your patient’s exams. Only you hold the keys, so not even employees of easyRadiology can access your data.

Your exams are stored in an encrypted ZIP archive
The encrypted images are loaded from the server and are decrypted in your browser
The password is only known to you
Using latest technologies it is impossible to break the encryption
The password is never transfered to our server (but remains in your browser)
You can audit us

More arguments for EasyRadiology

A cryptography professional says…

“Encryption is the single best hope for fighting surveillance of any kind. If all our data, including our communications, were enciphered in this fashion, from end to end…then no government – no entity conceivable under our current knowledge of physics, for that matter – would be able to understand them.”

The keys only belong to you!

easyRadiology does not have or store the encryption keys to your uploaded medical exams. For radiologies special server software is used, which runs easyRadiology on hospital servers. The encryption keys for the exams are issued in a document, which is easy to read and understand for the patients.

Using standards

easyRadiology uses industry standards for its file format and for encryption, which help to greatly reduce the likelihood of flaws in the code and security breaches. The file format is a standard ZIP and the encryption is performed with AES (256 bits).

No chance for intruders

Even if a hospital server with a local easyRadiology installation is compromised, the intruders will find that patient’s radiology exams are all encrypted and unreadable.

State-of-the-art encryption technology

In an age, where hospital servers are intertwined with the internet, there is always the threat of data security issues such as patient data being leaked out to the open. In our company easyRadiology, we take data protection very seriously, as we recognize that every single radiology “DICOM” file can carry sensitive patient records.
Our company has a track record of security knowledge, particularly with encryption software. Dr. Weihrauch started developing encryption tools during his medical school (“Crypt”, C++) and improved upon his skills with the open source project “NoSSL, JS/PHP”. Recently, he developed a cryptography project specifically for easyRadiology (Net-Core-JS-Encryption-Decryption, .NET Core / JS).

Pay us an unscheduled visit and audit us!

It’s not easy to trust some company on the internet. Therefore, we offer anyone to visit us unscheduled (or scheduled, if you prefer) to have a look at our servers and internet operations. Please bring a laptop and a radiology exam. Then, you can upload the radiology exam’s files from your laptop through easyRadiology while we take you through your radiology exam being processed on our servers! You will be able to track each of the processes and see for yourself that your radiology exam is fully encrypted with none of the patient data stored in our database or on our servers. This is why it is impossible – even for EasyRadiology employees – to access the patient data stored in a radiology exam.
The only thing we ask in return is that you publish your visit and the results online and we can link to it. Then, we can spread the word about our data-conscious processes!

EasyRadiology publishes uts encryption algorithms for all!

It is a good practice to publish the encryption code as open-source, so that anyone can scrutinize the security of the solution line by line and check the result of the encryption.

1. Encryption of the DICOM CD folder

The easyRadiology Image format (ERI) is a ZIP archive. It contains the entire original DICOM data (the CD/DVD folder) encrypted with AES-256. When you download the ZIP file and open it, you will see a folder labeled “DICOM_CD”. To extract files or the entire directory, please use a ZIP software like the free 7-ZIP or WinRAR. Windows’ built in extractor does not support the AES-256 encryption in ZIP files. If you are regularly extracting exams from other radiologies, we can provide you with specialist software connected to a QR code scanner to speed up the process.

The DICOM_CD folder is encrypted with a password, which has a format of 4x 8 (=32) characters separated by “-“. This has a randomness of 2.3 x 10^57, which corresponds to 192 bits. With current technologies, AES with a 192 bit password cannot be broken.

2. Encryption of the patient data

The patient data is stored alongside preview images in the ZIP container in a JSON file. This JSON file is encrypted with a 32 byte key (256 bits) with AES-256. The key is generated from the Exam Access Code. The “Exam Access Code” was chosen as a means that physicians and patients can enter the code easily on the website of EasyRadiology or the radiology. The “Exam Access Code” uses only 9 characters (3 x 3, separated by “-“), which are A-Z (without “O”) and 1-9 (without “0”). This results in a randomness of 35^9 = 7.8 x 10^13. easyRadiology uses the key derivation algorithm “Scrypt” with settings which make key derivation from the “Exam Access Code” extremely computationally heavy and hence very secure. On modern hardware and with default parameters, the cost of cracking the password on a file encrypted by Scrypt is approximately 100 billion times more than the cost of cracking the same password on a file encrypted by regular (open)SSL – this means that a five-character password using Scrypt is stronger than a ten-character password using openssl.” (from tarsnap.com).

3. Encryption source code online

Please have a look at the source code, which we developed and are using in easyRadiology here: https://github.com/smartinmedia/Net-Core-JS-Encryption-Decryption

Risk assessment

Let’s assess the risks:

Intrusion into easyRadiology server

Assuming a hacker is able to access the database and read all data from it, all they will be able to find will be encrypted exams. If they want to brute-force crack the password of only one single radiology exam, they would attack the “Exam Access Code”, because attacking the ZIP AES-256 (192 bit key) is futile. Because of the settings used for Scrypt to generate the key from the Exam Access code, it takes an average of 250 ms per key derivation on a i7 machine. To calculate 50% of all possible keys, this machine would need appr. 250,000 years (a very conservative estimate). Even with 250,000 computers calculating many keys simultaneously, there would only be 50% chance of cracking only one radiology exam by the end of the year. For 2 radiology exams you would need the double amount of time or computers, because the access codes and the salt vary between each radiology exam. Using pre-computed rainbow tables would not help the attacker because the key is salted before Scrypt is applied. This is not even taking into account that the time taken to check each derived single key applied against the encrypted file to determine if it is correct. The chance of anyone heavily investing such a huge amount resources and money to crack only one single radiology exam is highly unlikely.

Sending out email with exam keys

Sending out the email to the user with the radiology exam keys is actually a more realistic threat to security and should be used at the user’s discretion. The possible attack can be either from the email service provider (reading your emails) or from anyone who can access your emails on your computer. We will implement another means of encryption on this webpage, namely using an offline-converter and uploading the result to our cloud or having the radiology exam pre-anonymized in your browser. Alternatively, you can the “Exam Access Code” after upload on the website instead of an email. However, we think that most users / patients would prefer a simple service and accepting the risk of their unsecure emails.

Losing documents containing codes

This is actually the most realistic scenario: a patient loses his document with passcodes and someone else can view his exam. However, this is already a current risk with a patients having a copies of their own radiology exam reports.

Summary

Realistically, easyRadiology offers excellent security which outperforms competing solutions in cryptography. The threat of all patient’s data are exposed to hackers, are negligable because of the applied technologies.
However, we are always constantly scrutinizing our technology constantly for possible improvements and are always grateful for recommendations from anyone!

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Data security