Facebook stored the passwords of hundreds of millions of its users in plain text inside its internal systems, the social media giant has revealed.
"As part of a routine security review in January, we found that some user passwords were being stored in a readable format within our internal data storage systems. This caught our attention because our login systems are designed to mask passwords using techniques that make them unreadable," said Facebook's VP of engineering, security and privacy Pedro Canahuati in a blog post[1].
Canahuati said as a precaution Facebook will be notifying everyone whose passwords were stored in this way. Facebook said the passwords were never visible to anyone outside of the company and that is has found "no evidence to date" that anyone internally abused or improperly accessed them.
Facebook said it will have to notify hundreds of millions of Facebook Lite users, tens of millions of other Facebook users, and tens of thousands of Instagram users. Facebook Lite is a version of Facebook predominantly used by people in regions with lower connectivity.
In line with best security practices, Facebook said that in general it masks people's passwords when they create an account so that no one at the company can see them.
"In security terms, we 'hash' and 'salt' the passwords, including using a function called "scrypt" as well as a cryptographic key that lets us irreversibly replace your actual password with a random set of characters,"