In this age of fast-paced world, individuals and companies prefer to store their huge amounts of data, likely confidential on laptops, servers, hard drives, memory cards, and other storage media. So, whether you are upgrading your machine, repurposing systems, or disposing old drives, it is important to make sure that the sensitive is not accessible and cannot be recovered by other entities. In regard to this, you will need an efficient and secure data sanitization i.e. cryptographic erase.
This technology has been widely adopted since it presents a faster, more efficient, and economical way of making stored data unreadable. Instead, the conventional approaches of data erasure, where attention was paid to the overwriting data sectors, cryptographic erase makes data unreadable by deleting the keys that decode it.
In this guide, we will discuss cryptographic erase definition, process, advantages, types of implementation, and comparison to secure erasure.
What Is Cryptographic Erase?
The technique saves a lot of time compared to traditional approaches to remove digital footprints.
How Does Cryptographic Erase Work?
Step 1: Data Encryption
During writing of the data into the storage media, automatic encryption takes place using a data encryption key (DEK). The encryption process happens within the storage media itself.
Step 2: Data Encryption Keys Management
Encryption keys are stored in the firmware or hardware security module of the storage media. It is impossible to decrypt the data without knowing the key.
Step 3: Erasure Procedure Initiation
In case of the storage media nearing its end of life or reuse, an erasure procedure can be initiated by the administrator.
Step 4: Key Destruction
The key that enables decryption of the data is deleted. It is the most important step in cryptographic erasing since the key is the means of decrypting the data.
Step 5: Verification
Verification checks on most enterprise-grade solutions ensure successful key deletion. After successful verification, the encrypted data can no longer be accessed.
Since just the encryption key gets deleted and not all the data blocks on the drive, the operation can be performed in mere seconds to minutes, irrespective of the size of the drive.
Advantages of Cryptographic Erasure
Cryptographic erasure is becoming more popular due to the various benefits it offers.
- Fast Data Sanitization
Overwriting takes time especially when working on large storage drives. Since cryptographic erasure simply deletes encryption keys, sanitizing terabytes of data is possible in no time.
- More Secure
By deleting the encryption keys, it prevents the data from ever being recovered. Even powerful forensic recovery programs cannot recover data lacking the key.
- Reduced Hardware Wear
Overwriting multiple times may result in deterioration of SSDs or flash drives. The use of key deletion avoids unnecessary writing cycles and increases hardware longevity.
- Economical Process
As the process does not take much time or effort, it makes it a very economical approach for corporations dealing with substantial storage capacities.
- Compliance
Many regulations mandate that organizations dispose of their data securely. Cryptographic sanitization may assist corporations in meeting their requirements under the legislation regarding data protection and security.
Methods of Implementation for Cryptographic Erase
Depending on the environment, there are different ways to implement cryptographic sanitization of data.
#1: Self-Encrypting Drives (SEDs)
Self-Encrypting Drives automatically encrypt all data written on the drive through hardware-based encryption.
Process:
- Data encryption occurs during writing to the drive.
- Encryption keys are saved inside the drive.
- An erase instruction leads to deletion of encryption keys.
- Sanitization of the drive is automatic.
Advantages:
- Very quick sanitization process.
- Little consumption of system resources.
- Excellent security controls.
#2: Software Encryption Systems
This type of sanitization method is the software-based encryption method such as BitLocker and others.
Approach:
- Data is encrypted with keys generated by software.
- Keys are kept in safe vaults.
- Keys are destroyed by administrators for sanitization purposes.
- Encrypted data is rendered unintelligible.
Pros:
- Simple integration with existing systems.
- Suitable for endpoints and servers.
- Can be centrally managed.
#3: Enterprise Storage Arrays
Enterprise storage arrays use encryption and key management functionalities.
Process:
- Data gets encrypted throughout all storage systems.
- The encryption keys are centrally stored.
- Key deletion is performed by using consoles.
- Storage devices can be easily re-tasked.
Benefits:
- Scalability in a larger deployment scenario.
- Central management.
- Ensures compliance.
#4: Cloud-Based Environment
Encryption is commonly used by cloud vendors to secure their client data.
Process:
- The data is encrypted prior to storage.
- The encryption keys will be controlled by cloud key management services.
- They will be deleted once data needs to be sanitized.
- The encrypted data becomes unreadable.
Benefits:
- Ideal for virtual environments.
- Can be used for large cloud infrastructures.
- Makes secure data deletion easier.
Cryptographic Erase vs. Secure Erase
One of the most common comparisons in data sanitization is that of cryptographic erase vs. secure erase.
| Feature | Cryptographic Erase | Secure Erase |
| Method | Deletes encryption keys | Overwrites storage blocks |
| Speed | Very fast | Slower for large drives |
| SSD Wear | Minimal | Can increase wear |
| Requirement | Encrypted storage | Works on encrypted and non-encrypted drives |
| Data Recovery | Practically impossible without key | Data overwritten and unrecoverable |
| Scalability | Highly scalable | Time-consuming for large environments |
In the comparison between cryptographic erasure and secure erasure, what needs to be considered is the presence of encryption. For the former, encryption allows the quick erasure of data through the destruction of keys.
On the other hand, the use of secure erasure still remains an acceptable technique in data erasure for non-encrypted storage devices.
Alternative Solution for Secure Data Wiping
Best Practices to Follow While Conducting Cryptographic Erase
For the sake of ensuring maximum protection, one must follow these best practices while conducting cryptographic erasure:
- Ensure that encryption is enabled from the beginning.
- Use approved algorithms for encryption.
- Adopt key management system.
- Confirm the success of key destruction process.
- Keep track of all log files.
- Periodically review data disposal policy.
What are the Limitations of Cryptographic Erase?
Despite the high effectiveness and safety associated with cryptographic erase, there are certain issues related to this sanitization approach. Businesses should take them into account when deciding whether to use cryptographic erase as the main approach to destroying data.
- It Needs Previous Data Encryption
The main disadvantage of cryptographic erase is the need for encryption in order for it to work. Without proper data encryption, even deletion of encryption keys will not make the data unavailable.
Outcome: If data is not encrypted, it might still be available on the storage medium after performing cryptographic erase.
- It Is Vulnerable to Key Management Issues
As cryptographic erase is completely dependent on encryption keys, proper management of these keys becomes very important.
Outcome: Poor key management might lead to failure of the entire data sanitization procedure.
- Not Supported by All Storage Devices
Some of the older hard drives, storage systems, and consumer-level devices lack the capability to enable SED technology and the feature of cryptographic erase.
Implication: Other forms of disk sanitization such as secure erase or data overwriting may have to be employed.
- Verification May Prove Difficult
Unlike other overwriting-based techniques, where the change in the sector takes place at a physical level, with cryptographic erasure, it happens by way of eliminating the keys. In some cases, verification of the elimination process can pose difficulties.
Implication: Audits and other forms of validations will be required for compliance purposes.
- Unsuitable for Damaged Devices
When the storage drive is damaged or has hardware issues or cannot be accessed due to corruption, cryptographic erasure may prove impossible.
Implication: Physical destruction may have to be performed.
- Risk of Key Recovery
In case the encryption keys have been stored in any form of backups, recovery software, escrow, or another storage facility, it is possible to decrypt the data after erasure.
Impact: The failure to eliminate keys leads to vulnerabilities.
- Residual Metadata Can Be Available
There are cases where some system metadata, logs, or configuration settings may be found outside the scope of the encrypted data.
Impact: Even though the data itself is not available anymore, some traces can give out clues about what happened before.
Final Takeaway
Cryptographic erase has proved to be one of the most effective ways of wiping out the information from storage media that have been encrypted with the help of encryption keys. By eliminating the encryption keys, rather than erasing all of the drives in a storage device, companies will be able to render their information unusable in a quick manner.
Due to the increase in the amount of storage available, the conventional method is becoming less convenient due to the large amounts of time needed. Cryptographic erase becomes advantageous especially to companies, in the cloud environment, and in self-encrypting drives. Understanding the difference between cryptographic erase and secure erase becomes quite useful too.
By understanding both concepts effectively, you will be able to come up with a great decision regarding which process is best for you.
