Crypto Anchors: Exfiltration Resistant Infrastructure
Another form of &quot;crypto anchor&quot; is Blind Hashing which uses a large pool of random data to defend the hashes. An attacker would need to exfiltrate over 90% of the data before they could run an offline attack on hashes blinded by the data pool. The bigger the data pool, the more data an attacker would have to steal, and the more hashes&#x2F;sec you can run.<p>So while iterative&#x2F;computational hashing is only secure if it is slow and if the password is strong, Blind Hashing prevents offline attacks even against weak passwords and actually runs faster as you increase the cost factor.<p>In this case it&#x27;s more like an an actual anchor -- technically we call this Bounded Retrieval Model -- the idea that we size the network bandwidth to make it take 300 days at full line rate to steal the data over the network. So it&#x27;s a physical limitation rather than trusting a black box to protect 256 bits like an HSM.<p>If you&#x27;re interested here&#x27;s an intro [0], a tech spec [1], and an academic paper [2] by Moses Liskov at MITRE.<p>Disclaimer: I&#x27;m Founder&#x2F;CTO of BlindHash.com which is basicallly Data Pool as a Service -- we provide an API into a geo-replicated 16TB (and growing) data pool.<p>[0] - <a href="https:&#x2F;&#x2F;s3.amazonaws.com&#x2F;blindhash&#x2F;BlindHash+Architecture+Guide.pdf" rel="nofollow">https:&#x2F;&#x2F;s3.amazonaws.com&#x2F;blindhash&#x2F;BlindHash+Architecture+Gu...</a><p>[1] -  <a href="https:&#x2F;&#x2F;docs.wixstatic.com&#x2F;ugd&#x2F;005c1c_5996c661899e4d09a28b9aa373c090c8.pdf" rel="nofollow">https:&#x2F;&#x2F;docs.wixstatic.com&#x2F;ugd&#x2F;005c1c_5996c661899e4d09a28b9a...</a><p>[2] - <a href="https:&#x2F;&#x2F;eprint.iacr.org&#x2F;2017&#x2F;917.pdf" rel="nofollow">https:&#x2F;&#x2F;eprint.iacr.org&#x2F;2017&#x2F;917.pdf</a>