# The Quantum Computing Threat to Cloud Storage Explained In this article - [How Classical Cloud Storage Encryption Works Today](#how-classical-cloud-storage-encryption-works-today) - [What Is Quantum Computing and Quantum Computers?](#what-is-quantum-computing-and-quantum-computers?) - [How Quantum Computers Threaten Cloud Storage Encryption](#how-quantum-computers-threaten-cloud-storage-encryption) - [Why End-to-End Encrypted Cloud Storage Alone Is No Longer Enough](#why-end-to-end-encrypted-cloud-storage-alone-is-no-longer-enough) - [What Is Post-Quantum Cryptography?](#what-is-post-quantum-cryptography?) - [Quantum-Resistant Cloud Storage To Protect Your Files](#quantum-resistant-cloud-storage-to-protect-your-files) In this article- [How Classical Cloud Storage Encryption Works Today](#how-classical-cloud-storage-encryption-works-today) - [What Is Quantum Computing and Quantum Computers?](#what-is-quantum-computing-and-quantum-computers?) - [How Quantum Computers Threaten Cloud Storage Encryption](#how-quantum-computers-threaten-cloud-storage-encryption) - [Why End-to-End Encrypted Cloud Storage Alone Is No Longer Enough](#why-end-to-end-encrypted-cloud-storage-alone-is-no-longer-enough) - [What Is Post-Quantum Cryptography?](#what-is-post-quantum-cryptography?) - [Quantum-Resistant Cloud Storage To Protect Your Files](#quantum-resistant-cloud-storage-to-protect-your-files) [Blog](/blog/)/The Quantum Computing Threat to Cloud Storage Explained Security # How Quantum Computing Threatens Cloud Storage Encryption July 31, 20268 min readWhile many viewed quantum computers as science fiction, [Google published an article](https://blog.google/innovation-and-ai/technology/safety-security/cryptography-migration-timeline/) on 25 March 2026 outlining a timeline to complete its migration to post-quantum cryptography by 2029. The next month [Cloudflare targeted](https://blog.cloudflare.com/post-quantum-roadmap/) 2029 for full post quantum security and migration. The writing was on the wall, Q-day or the moment when quantum computers become powerful to break current encryption standards was not to be taken lightly. For years, [end-to-end encrypted cloud storage](/blog/end-to-end-encryption/) platforms were considered safe and secure. However, the emergence of quantum computing has threatened cloud storage encryption in many ways. From Shor's algorithm theoretically breaking public key cryptography to [Harvest Now, Decrypt Later](/harvest-now-decrypt-later/) threats, your data may not be encrypted forever. In this guide, we will talk about why powerful quantum computers pose a threat to current cloud storage encryption standards. We will also discuss why end-to-end encryption is not sufficient alone and has to be paired with [post quantum encryption](/post-quantum-encryption/). Moreover, we shed light on NIST recommended PQC standards and how DragBin has adopted them to secure your data. ## How Classical Cloud Storage Encryption Works Today If you're using an encrypted cloud storage, your cloud storage provider secures your data using a combination of encryption methods. We have explained these below, using an example of John Doe uploading his medical records. ### TLS for Data in Transit Transport Layer Security (TLS) protects your data by encrypting it while it travels between your local device and the cloud server. This prevents attackers from getting their hands on your data if they intercept the internet connection. For example, when John Doe uploads his medical records, TLS creates a secure, encrypted connection. ### RSA/ECC for Key Exchange RSA and ECC (Elliptic Curve Cryptography) are public-key cryptographic algorithms used to securely exchange encryption keys. The former relies on integer factorization of large prime numbers while the latter uses mathematics of elliptic curves. It is important to note that they do not encrypt the file rather create a secure connection for key change. Using our previous example, before John Doe's medical records are uploaded, this device must agree on a shared encryption key with the cloud server. Here comes the role of RSA/ECC that ensures only John Doe's device knows the key. ### AES-256 for File Encryption Majority of the cloud storage providers use AES-256 (Advanced Encryption Standard) for file encryption. This is a symmetric encryption algorithm that encrypts the contents and protects your data at rest. Therefore, when John Doe's medical records reach the cloud server, it is encrypted using AES-256 before being stored on the provider's system. ## What Is Quantum Computing and Quantum Computers? Having gone through classical cloud storage encryption, we will now look at the concept of quantum computers. Before we proceed, you should know that today's emerging quantum computers do not have the ability to break RSA, etc. However, despite the threat being distant, it has pushed companies to adopt quantum resistant encryption. In simple terms, quantum computing is a new type of computing that uses quantum mechanics to process information. While normal computers store your data in regular bits like 0 or 1, quantum computing uses qubits. This means that your information can exist as 0, 1 or a combination of both, in what we now know as superposition. That being said, quantum computers use qubits and can solve problems at a much faster level. According to [IBM](https://www.ibm.com/think/topics/quantum-computing#Quantum+computing%2C+defined), "qubits have access to more complex mathematics for a different type of computation...due to quantum mechanical concepts known as superposition and interference." While there is a lot to quantum computing, we must understand why quantum computers pose a threat to your data in cloud storage. ## How Quantum Computers Threaten Cloud Storage Encryption One reason quantum computers are considered so powerful is their ability to factor very large numbers much more efficiently than classical computers. ### Shor's Algorithm and Public-Key Cryptography We have already mentioned that RSA depends on integer factorization and ECC revolves around discrete logarithm problem over elliptic curves. For regular computers, these problems have remained computationally impractical to solve. For this reason, governments, banks and other institutions use them for secure internet communications. Things changed in 1994, when a mathematician named Peter Shor developed a quantum algorithm, which is now popularly known as Shor's algorithm. He theoretically proved that strong quantum computers could solve mathematical problems far more efficiently than classical computers. This means that a powerful quantum computer could quickly factor large integers and compute discrete logarithms. If this happens, the whole foundation of RSA and ECC would crumble since they are built on mathematical problems that are difficult to reverse. The attacker would then abuse this to derive private keys from public keys. Once the keys are compromised, the data and other encrypted communications will be exposed. ### Grover's Algorithm and Symmetric Encryption Lov Grover developed the Grover's algorithm in 1996 that uses quadratic speedup to search for a specific item in an unstructured database. Applied to encryption standards, this would mean that a quantum computer has greater advantage over normal computers in guessing the encryption keys. This affects symmetric encryption like AES 256 and attackers will potentially abuse this during brute force attacks. To understand this better, let us take a simple example of a safe with billions upon billions of possible keys. A normal computer would eventually have to test each one individually which would take an imaginable amount of time. On the other hand, a powerful quantum computer can search faster, reducing the time needed to find the correct key. That being said, AES 256 is still extremely secure and Grover's algorithm does not deconstruct it. A quantum computer could possibly reduce 2²⁵⁶ possible operations to 2¹²⁸ operations which is still computationally infeasible. However, this sheds light on how symmetric encryption is not completely immune to quantum computing. ## Why End-to-End Encrypted Cloud Storage Alone Is No Longer Enough ### Harvest Now, Decrypt Later Attacks Harvest Now, Decrypt Later (HNDL) or Store Now, Decrypt Later (SNDL) threats are a big concern around quantum computing. While powerful quantum computers are yet to come, attackers can intercept and store your encrypted files today. When sufficiently powerful quantum computers are available, they will decrypt the stolen data. This is extremely dangerous for governments, military organisations, banking, medical or any industry that deals with sensitive information. Your data may be encrypted today but using HDNL attacks, it may be on the verge of being exposed. Both, organisations and individuals alike should protect themselves and migrate to quantum resistant platforms. ### End-to-End Encryption Still Relies on Secure Key Exchange Many cloud storage providers offer end-to-end encryption but before the file is encrypted, a secure connection must be established. The keys for both encryption and decryption need to be exchanged over a secure network. Since end-to-end encrypted cloud storage still relies on RSA/ECC, we have already discussed why it is vulnerable to quantum computers. This does not mean end-to-end encryption in cloud storage is not important, rather it is not sufficient alone. If you want long term protection, [e2ee](/e2ee-encryption/) needs to be paired with quantum resistant encryption or post-quantum cryptographic algorithms for key exchange. For this reason, DragBin uses neither standard RSA nor ECC for its core file encryption, relying instead on ML-KEM (Kyber) post-quantum cryptography. ## What Is Post-Quantum Cryptography? As the name suggests, post quantum cryptography is designed to protect your data from classical computers as well as future quantum computers. It replaces vulnerable public-key algorithms like RSA and ECC used for key exchange and digital signatures. In terms of encryption, post quantum cryptography continues to rely on AES-256 for protecting data. There are post-quantum cryptography standards which are finalized by the [U.S. National Institute of Standards and Technology (NIST)](https://www.nist.gov/). Two of the most important standards are :- ML-KEM (formerly CRYSTALS-Kyber) for key change - ML-DSA (formerly CRYSTALS-Dilithium) for digital signatures While classical cryptography (RSA/ECC,etc) relies on number-theoretic problems like integer factorization and discrete logarithms, NIST's standardized algorithms are based on lattice-based cryptography. In simple words, they solve complex mathematical problems within high-dimensional lattices instead of large number calculations. ## Quantum-Resistant Cloud Storage To Protect Your Files In response to the threats posed by quantum computing, DragBin emerged as one of the world's first quantum-resistant cloud storage platforms. On top of client side, end-to-end encryption, we offer post quantum encryption (ML-KEM) plus AES 256. Our [security architecture](/security/) is completely [zero-knowledge](/zero-knowledge-encryption/), with its design and security practices detailed in our [security whitepaper](/whitepaper/). Our goal is to offer a genuine storage solution for all users, whether they are on the basic/[free plan](/free-cloud-storage/) or a paid subscription. We support the right to privacy and your files are completely safe with us. Nobody, not even the employees at DragBin can see your files, folders, passwords, filenames, etc.- You get [secure file sharing features](/features/secure-file-sharing/) with password protected links, view limit, download limit, geo-restrictions, etc. - Unlimited file size uploads, unlimited bandwidth and unlimited sharing for all users - Preview videos in 4k/8k and Integrated global CDN for lightning fast download/upload If you are an organization seeking a [secure cloud storage for business](/features/secure-cloud-storage/), [DragBin for Business](/business/) is the way to go. In an age of HNDL attacks, your sensitive documents and confidential information remain safe with our quantum resistant cloud storage. Utilize virtual data rooms, version history, role based permissions, encrypted e-signatures and granular access logs among other features in a consolidated workflow. [Switch to DragBin](https://app.dragbin.com/signup) Share this article Share on FacebookShare on TwitterShare on LinkedInShare via EmailCopy link secure by design ## Experience end-to-end encryption with DragBin Protect your sensitive files with zero-knowledge, post-quantum encryption. Try DragBin and truly own your data. [Start free](https://app.dragbin.com/signup) Newsletter ## Stay updated on security trends The latest privacy and security insights, delivered to your inbox. Subscribe Keep reading ## Related articles [July 23, 2026-8 min read ### What Is End-to-End Encryption? How It Works Explained Learn what end-to-end encryption is, how it works, how it differs from standard encryption, benefits and why it keeps your files and messages truly private. Read article](/blog/end-to-end-encryption/)[February 28, 2025-12 min read ### Zero-Knowledge Architecture: The Future of Cloud Security and True Data Ownership Discover what Zero-Knowledge Architecture means for cloud security. Learn how this revolutionary model protects your data from breaches and surveillance, and how dragbin gives you true ownership of your files with client-side, zero-knowledge encryption. Read article](/blog/zero-knowledge-architecture/)[July 21, 2026-8 min read ### Secure File Sharing with DragBin: Share Files Safely in 2026 Securely share files with DragBin using end-to-end encryption, password-protected links, expiration dates, VPN blocking, watermarks and advanced controls. Read article](/blog/secure-file-sharing/) --- Canonical: https://www.dragbin.com/blog/quantum-computing-cloud-storage