What is the most effective data erasing technique for any storage media?

This blog discusses the many data erasure technique for erasing magnetic storage media like Hard Drives and tapes, as well as flash storage media like SSD, pen drives, SD cards, and internal storage of Android or iPhone.

You may have many data storage devices holding critical information, such as customer personal data and business intelligence, as part of your firm. To comply with data protection rules and protect your business from data breach threats, effective erasure of this data is critical.

Knowing the proper data erasure technique for certain storage media types is critical in the overall data destruction plan. In an ideal world, your company would seek out the optimum data erasure method for any form of storage media, including rack-mount servers, RAID, NAS, laptops/PC, standalone hard drives and SSD, flash storage, and so on.

Different types of data erasing technique for various media types

Before digging into the data erasure methods, keep in mind that “data erasure” officially refers to overwriting memory regions on a storage medium with binary patterns such as ones and zeros. Data erasure may also include running a device-specific Block Erase operation or cleaning the cryptographic key in Self-Encrypting Drives in some cases (SEDs). Data erasure, on the other hand, does not imply that files are permanently deleted by using the SHIFT + DEL keys on Windows or the Option + Command + Delete keys on macOS. You may learn more about the differences between data erasure and data deletion in our blog post.

The various forms of data erasing technique are as follows:

  1. Overwriting

This approach overwrites all user-addressable memory regions on a storage device with non-sensitive data such as random binary patterns, including logical storage places like the file allocation table. Overwriting seeks to replace the target data in such a way that it is permanently lost, with no way of recovering or retrieving it. 

Application Scope of Overwriting

The following data storage media can be erased using the overwriting method or technique.

  • Floppies
  • Magnetic disks and tapes
  • Hard Disk Drives (HDD)
  • Solid State Drive (SSD)
  • Memory cards
  • Electronically Erasable Programmable Read-Only Memory (EEPROM)

Overwriting Techniques to Ensure Data Erasure

Using device-specific commands and data erasing software based on the following approaches, data erasure by storage media overwriting is possible:

  1. Block Erase

In a SSD, the Block Erase method erases data by providing a significantly high voltage level to all NAND cells, including retired, reallocated, spare, and over-provision cells. Block Erase wipes flash memory-based storage medium using device-specific commands, and the output are commonly 0s and 1s. The Block Erase approach is classified as a Purge method by the NIST SP 800-88 Guidelines, and it is based on the use of specialised and standardised commands to erase SSDs.

Application Scope of Block Erase

The following data storage media can be erased using the block erase method or technique.

  • All types of SSD (ATA, PATA, SATA, SCSI and other)
  1. Cryptographic Erase

Cryptographic Erase (CE) or crypto scramble sanitises the Media Encryption Key (MEK) used to encrypt data on a Self-Encrypting Drive (SED), resulting in ciphertext or encrypted data on the drive. The MEK is erased using the CRYPTO SCRAMBLE EXT instruction. Cryptographic Erase is faster than overwriting and Block Erase since it does not work on the storage locations (i.e. sectors or blocks). The gap in total erase time between CE and other data erasure technologies grows as the device’s data store capacity grows. Cryptographic Erase falls into the Purge group of media sanitization methods, according to the NIST rules.

Application Scope of Cryptographic Erase

The following data storage media can be erased using the Cryptographic Erasemethod or technique.

  • Apple iPhone and iPad
  • Android devices
  • ATA, NVM Express and SCSI SSD

Final ThoughtsBased on the type of storage medium and usage conditions, this blog discussed the various data erasure methods. The goal is to provide a broad overview of the various possibilities and assist you in making an informed decision on the optimal data erasure method. Despite the fact that various approaches coexist and are relevant depending on the situation, knowledge, and demand. You can also use certified data erasure solution like BitRaser Drive Eraser Software that will help you erasing/wiping data from all types of storage device beyond the scope of recovery. Verifiability is a critical issue, in addition to criteria like effectiveness and efficiency, because having a certified solution may assist your firm show data protection and compliance with current legislation.