1. Business
January 12, 2022

Crypto-shredding the best solution for cloud system data erasure

By GlobalData Thematic Research

Crypto-shredding is an accurate and cost-effective compliance solution to Article 17 of the GDPR, the ‘Right to Erasure’. It is cheap and works effectively across distributed cloud systems, where archived data might be inaccessible to the data controller.

However, crypto-shredding is only as effective as the encryption service used to protect the data in the first place. With cyberattacks becoming more sophisticated year on year, crypto-shredding may not be the most future-proof solution if encrypted data can be hacked.

Even so, crypto-shredding is the cheapest and most effective current solution for data retention and erasure compliance for large companies using distributed cloud systems.

Crypto-shredding and the GDPR

Crypto-shredding is the deletion or overwriting of the encryption keys that give access to encrypted data. Destroying the key to the encrypted data means it cannot be accessed and that data is effectively deleted because it is unreadable.

Under Article 17 of the GDPR, also referred to as ‘the right to be forgotten’, data subjects can request that all their personal data be deleted and cease to be processed. The request must be fulfilled completely and with ‘undue delay’.

Destroying the encryption key to personal data is accurate and instant, leaving data unreadable and effectively destroyed. However, crypto-shredding only works for encrypted data and is only as strong as the original data encryption.

Cheap, centralized, and cloud compliant

Crypto-shredding is the best solution for big companies operating over distributed cloud systems. In these systems, personal data can be duplicated or taken out of the company’s immediate control. Destroying encryption keys ensures no one can access the data, even when there are many distributed copies.

It is also significantly cheaper than outright deleting personal data, because companies can centrally manage encryption keys, without transmitting datasets over a wide area network (WAN) in order to delete them.

Crypto-shredding enables the centralized control of user data across distributed systems, allowing for the instant removal of data as soon as the user opts out.

Spotify is using crypto-shredding

Spotify has created a scalable user privacy system called ‘Padlock’, which uses crypto-shredding for opt-out requests from users. Each user has a unique key: removing or overwriting one key in one place causes a user’s data to be inaccessible and effectively deleted.

Senior Engineer at Spotify Bram Leenders explained: “If a user asks us to stop processing or storing their data, all we need to do is remove the key belonging to that user, in one place. We don’t need to worry about contacting every system that might store that data. We only remove one key in one place.”

Crypto-shredding is the most efficient and cost-effective way for big companies with distributed cloud systems to comply with data retention and erasure regulations. However, companies should be aware it will only be as effective as its data encryption. Strong data encryption should always be deployed to protect user data.