BREECH attacks and Noise

This feature has been part of the Rdbhost service for many weeks, but I have never mentioned it before now.

First, let me describe the threat addressed, before going into how it is addressed.

Breech Attack

The BREECH attack is a way to compromise SSL/TLS encryption in HTTP transfers that also involve compression.

The attack relies on a given request always getting the exact same response. By resubmitting the request with tiny variations and looking at the changes in the response size resulting from changes in the compression ratio, inferences can be drawn by the attacker about the content that was compressed.

This attack can be countered by ensuring that submissions of the same request get slightly difference response values and/or sizes.'s solution is to include some noise in every response body. It adds a field, called 'noise', at the root level of the JSON data object. The field value is 8 to 12 random alphanumeric characters.

This small variation in the consecutive responses to the same request should effectively negate the BREECH attack.

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