AWS vs Azure vs GCP: Database Encryption Compared

Choosing the right cloud provider for database encryption is crucial for UK businesses navigating GDPR and other regulatory requirements. Here's a quick breakdown:

• AWS: Offers AES-256 encryption, TLS for data in transit, and advanced key management through AWS KMS. Ideal for businesses needing granular control but requires manual setup for some services. Compliance certifications include Cyber Essentials Plus and ISO standards. Pricing starts at £0.77/month per key.
• Azure: Provides AES-256 encryption with Transparent Data Encryption (TDE) enabled by default for Azure SQL databases. Azure Key Vault simplifies key management and integrates with Microsoft services. Strong UK compliance support with local datacentres. Transaction-based pricing.
• GCP: Encrypts all data by default with AES-256 and offers Cloud KMS for key management. Features the fastest key management latency (200ms) but FIPS 140-2 Level 1 compliance may not meet stricter security needs. Starts at £0.06 per 10,000 requests.

Quick Comparison

Each provider caters to different needs, so your choice depends on your business's existing infrastructure, compliance priorities, and key management preferences. AWS excels in control, Azure integrates well with Microsoft tools, and GCP simplifies encryption by default.

Secure by Default? Scoring the Big 3 Cloud Providers

AWS Database Encryption and Key Management

Amazon Web Services (AWS) employs a robust approach to database encryption, blending well-established protocols with flexible key management solutions. This setup gives UK businesses the tools they need to safeguard data and comply with regulatory requirements. Let’s break down the encryption standards, key management options, and compliance measures that are particularly relevant for organisations in the UK.

Encryption Standards and Database Services

AWS uses AES-256 encryption to secure data at rest across its database services, including RDS instances, DynamoDB, and Aurora. AES-256 is widely recognised as a secure encryption standard [3]. For RDS instances, this encryption extends to underlying storage, automated backups, read replicas, and snapshots [2].

To protect data in transit, AWS relies on SSL/TLS protocols. These secure the connection to database instances, and AWS has even developed its own TLS implementation, called s2n, which is designed to be lightweight, fast, and easy to audit [3][5].

AWS doesn’t stop there - it encrypts data at multiple levels: physical, network, and application. All API endpoints use TLS 1.3 by default, with TLS 1.2 as the minimum standard [3][4].

Encryption is a critical component of a defence-in-depth security strategy that uses multiple defensive mechanisms to protect workloads, data, and assets. - AWS Security Blog [3]

AWS Key Management Options

AWS Key Management Service (KMS) acts as a centralised solution for managing encryption keys. Users can create and control the keys used for encryption, which are stored securely inside FIPS 140-3 Security Level 3 validated hardware security modules (HSM). These keys are never stored unencrypted outside AWS KMS [6].

AWS provides several key management options:

• AWS managed keys: Automatically generated and rotated by AWS every three years.
• Customer managed keys: Offer more control, allowing businesses to create, delete, enable, and disable keys. These can be rotated automatically or manually on an annual basis.
• AWS CloudHSM: For organisations with the highest security needs, this service provides dedicated hardware security modules [8][9].

To ensure precise control, AWS KMS supports granular key policies, enabling businesses to restrict access to specific keys [6]. Integration with services like Amazon S3, Amazon EBS, and Amazon RedShift makes encryption across the organisation’s infrastructure seamless [8]. Additionally, AWS CloudTrail integration provides detailed auditing of key usage, which is essential for maintaining security and compliance [8].

In terms of cost, AWS KMS keys are priced at £0.77 per month (prorated hourly), with a free tier offering 20,000 requests per month [7].

Compliance and UK Requirements

AWS has a comprehensive compliance framework, supporting 143 security standards and certifications worldwide [10]. For UK businesses, AWS demonstrates adherence to local regulations through certifications like Cyber Essentials Plus. This certification was renewed in March 2025 after an IASME-certified independent audit of the AWS corporate network in the UK and Ireland. It remains valid until 21st March 2026 [12].

AWS also holds internationally recognised certifications, including ISO/IEC 27001:2022, 27017:2015, 27018:2019, and 27701:2019. These certifications highlight AWS’s ability to manage information security risks, implement cloud-specific security measures, and protect customer data privacy [11][15].

For GDPR compliance, AWS offers a range of tools, security features, and legal agreements, such as the AWS Data Processing Agreement and Business Associate Addendum. However, it’s important to note that the responsibility for achieving compliance ultimately lies with the customer [14].

At AWS, security is our top priority. We are committed to helping you control how your data is used, who has access to it, and how it is protected. - AWS Security Blog [3]

To make compliance easier, AWS provides AWS Artifact, a free self-service portal offering access to security and compliance reports. This helps UK organisations demonstrate their compliance posture to auditors and regulators [11]. For financial institutions, AWS advises assessing the significance of workloads, reviewing the Shared Responsibility Model, and notifying UK regulators when outsourcing agreements are deemed material [13].

Azure Database Encryption and Key Management

Microsoft Azure employs a thorough approach to database encryption, combining industry-recognised protocols with Azure Key Vault. This setup offers UK businesses robust security options while aligning with local regulations. Azure's encryption strategy provides protection at multiple levels, securing both data at rest and in transit, and integrates closely with its key management solutions.

Encryption Standards and Database Services

Azure relies on AES-256 encryption to protect stored data across its database services, including Azure SQL Database, Cosmos DB, and Azure Database for MySQL [16]. For Azure SQL Database, Transparent Data Encryption (TDE) serves as the primary method for safeguarding data at rest. TDE employs AES and Triple Data Encryption Standard (3DES) algorithms and is automatically enabled on all new Azure SQL databases, ensuring sensitive data is protected right from the start [16].

Azure offers flexibility with its encryption models, allowing organisations to choose between service-managed server-side encryption, customer-managed keys stored in Azure Key Vault, or on-premises keys [16]. For businesses requiring even stricter security, client-side encryption is available, enabling keys to be managed and stored in secure, external locations [16].

For data in transit, Azure uses TLS encryption, while Always Encrypted provides additional client-side protection for sensitive data [16]. Services like Azure Data Lake secure data in transit with HTTPS, and Azure SQL Database and Azure SQL Managed Instance allow organisations to enforce minimum TLS versions to meet specific security needs [17]. Both services comply with FIPS 140-2 Level 1 standards [17].

While encryption is critical, secure key management is equally important, and that's where Azure Key Vault comes into play.

Azure Key Vault and Key Management

Azure Key Vault acts as a centralised hub for managing encryption keys, secrets, and certificates, simplifying the process of securing cryptographic assets [18]. It supports both platform-managed keys (PMK) and customer-managed keys (CMK), with a Premium tier available for hardware security module (HSM)-protected keys [18][21].

Key Vault integrates smoothly with Azure services like Azure Disk Encryption, SQL Server, and Azure SQL Database, allowing stored keys to be used across multiple platforms without complex setup [18]. Its features include automated key rotation, key versioning, and detailed logging for enhanced security. Access control is managed through Microsoft Entra ID for authentication, alongside Azure role-based access control (RBAC) or Key Vault access policies for authorisation [18]. Additionally, Azure Key Vault ensures encryption at rest using keys stored in HSMs and integrates with monitoring tools like Event Grid, Microsoft Defender for Cloud, and Azure Monitor [20].

The pricing model for Azure Key Vault is transaction-based, with two tiers: Standard, which uses software-based keys, and Premium, which provides HSM-protected keys and includes an additional monthly fee per key [21].

Compliance and UK Requirements

Azure's encryption and key management solutions are designed with compliance in mind, meeting key UK regulatory standards. Microsoft's UK-based datacentres, established in 2016 in London, Durham, and Cardiff, support organisations in meeting GDPR requirements by ensuring data storage and processing remain within UK borders [25]. These datacentres hold certifications such as ISO 27001, 27018, and 27701, addressing information security and privacy management standards [25]. Azure also supports the UK Cyber Essentials Plus certification [23][25].

For GDPR compliance, Azure offers tools like Compliance Manager and Microsoft Purview to help UK businesses manage their obligations [25]. Additionally, Microsoft provides Standard Contractual Clauses to facilitate compliant data transfers outside the EU when required [24]. Azure Key Vault itself holds over 100 compliance certifications, including more than 50 tailored to specific global regions, further supporting regulatory needs [19].

Microsoft continues to invest heavily in UK infrastructure, committing £2.5 billion over three years to double its datacentre capacity [25]. To maximise security, organisations should utilise RBAC, enable automated key rotation, and conduct thorough audits using Key Vault access policies [22].

GCP Database Encryption and Key Management

Google Cloud offers a range of encryption and key management tools designed to meet the needs of businesses in the UK. By default, Google Cloud encrypts all data, ensuring a consistent layer of protection. This approach spans all services, leveraging advanced standards and flexible key management through Cloud KMS. The result? UK organisations benefit from automatic, high-level data security.

Encryption Standards and Database Services

Google Cloud employs AES‑256 encryption to secure data at rest across its database services, such as Cloud SQL, Firestore, and Bigtable. This encryption is applied automatically before data reaches any database system or physical hardware [26][27]. For data in transit, GCP uses TLS encryption, safeguarding information as it moves between services and clients [26]. Additionally, Google integrates the Tink cryptographic library, which includes a FIPS 140‑2 validated module (BoringCrypto), to bolster security measures [26]. AES‑256 encryption is widely regarded as a trusted standard, used extensively in government, military, and financial sectors [27].

Google Cloud Key Management Service

Cloud KMS offers a range of key management options, supporting both symmetric (AES‑256) and asymmetric keys (RSA 4096, EC P384) via REST APIs. Businesses can choose between Google-managed keys, CMEK, Cloud HSM, and Cloud EKM, depending on their specific requirements [28][29][30]. The service handles plaintext sizes up to 64KB and delivers an average latency of 200ms - outperforming similar services from AWS and Azure [29][32].

Pricing for Cloud KMS is structured on a subscription model, starting at approximately £0.06 per 10,000 requests, with HSM keys costing around £1 per key per month. Costs vary based on factors like protection levels and the number of active key versions [31][32]. While Cloud KMS holds a FIPS 140‑2 Level 1 compliance rating - lower than the Level 2 rating of AWS KMS and Azure Key Vault - it offers strong audit logging and integrates seamlessly with external key managers and hardware encryption tools [29][30]. These features provide a solid foundation for evaluating encryption performance and compliance in the next section.

Compliance and UK Requirements

For businesses in the UK, GCP supports GDPR compliance and aligns with regulatory expectations through ISO 27001 certification and detailed audit logging. ISO 27001 outlines an Information Security Management System (ISMS), helping organisations meet various legal and regulatory demands [33]. Additionally, GCP provides tools to assist businesses in fulfilling data protection obligations under GDPR [33]. However, organisations with strict data residency requirements should carefully assess Google's approach to data localisation.

For UK companies assessing GCP's encryption capabilities, the platform's default AES‑256 encryption and comprehensive key management options through Cloud KMS offer a reliable and cost-effective solution. However, businesses requiring the highest level of key protection should consider the FIPS 140‑2 Level 1 rating as part of their decision-making process.

Security, Performance, and Compliance Comparison

When comparing database encryption across AWS, Azure, and GCP, UK businesses need to carefully evaluate their security, performance, and compliance needs. The table below summarises key encryption features for each provider.

Summary of Encryption Features

This comparison highlights the differences in encryption features and capabilities among the providers.

Pros and Cons of Each Provider

Choosing the right platform for database encryption is a critical decision for UK organisations. Here’s a closer look at the advantages and limitations of each provider:

AWS offers a robust suite of over 500 security and compliance-focused features [1]. Its granular control through IAM and advanced threat detection tools, such as AWS Shield and WAF, make it a strong contender for organisations with complex regulatory requirements. However, encryption is not automatically enabled for all services, requiring manual configuration. AWS also provides extensive compliance certifications, including a UK GDPR Addendum that aligns with post-Brexit data protection regulations.

Azure integrates seamlessly with Microsoft environments, making it an attractive choice for businesses already using Office 365 or Windows-based infrastructure. Its Azure Active Directory delivers advanced identity management, while Azure Security Center provides comprehensive threat protection across hybrid cloud setups. This integration can simplify operations for UK businesses heavily invested in Microsoft ecosystems.

GCP takes a straightforward approach by encrypting all data by default, reducing the risk of human error during configuration [34]. It also boasts the fastest key management performance, with an average latency of 200ms compared to AWS's 300ms and Azure's 250ms. However, its FIPS 140-2 Level 1 compliance is lower than the Level 2 certifications of AWS and Azure, which may be a concern for organisations with stricter security requirements. Google Cloud also commits contractually to GDPR compliance across all services [35], ensuring alignment with evolving UK data protection laws.

AES-256 encryption, when applied selectively, has minimal impact on system performance. For UK organisations, compliance needs have shifted following Brexit. AWS addresses this with a UK GDPR Addendum, including Standard Contractual Clauses and the International Data Transfer Addendum from the Information Commissioner's Office [1]. Similarly, GCP remains committed to GDPR compliance, adapting to changes in regulatory landscapes [35].

The choice between these providers depends on factors such as existing infrastructure, specific compliance needs, and performance priorities. Financial institutions, for instance, must consider the requirements of the Data Protection Act 2018 when selecting encryption solutions [13]. Additionally, the recently enacted Data (Use and Access) Act 2025, which came into force on 19th June, introduces amendments to UK GDPR affecting areas like legitimate interests, direct marketing, and automated decision-making [37]. UK organisations should evaluate how these changes impact their compliance strategies when choosing a provider.

Choosing Database Encryption for UK Businesses

When it comes to picking the right database encryption solution, UK businesses need to weigh up regulatory compliance, operational demands, and costs. Each cloud provider brings something different to the table, catering to varying organisational needs and technical setups.

AWS stands out for businesses that need detailed control over encryption. With over 500 security features [1] and a UK GDPR-compliant addendum [1], it’s well-suited for companies with strict regulatory requirements. However, this level of customisation often means higher management complexity [13].

Azure is a great fit for organisations already invested in Microsoft’s ecosystem. Its seamless integration with Office 365, enterprise-grade key management through Key Vault, and straightforward data processing agreements make compliance more manageable [35].

For those prioritising simplicity, GCP is a strong contender. Its default encryption settings minimise the risk of misconfigurations and reduce operational complexity. Additionally, its contractual commitments ensure GDPR compliance [35].

Operational Demands

Each provider has its own operational requirements. AWS offers granular control but demands significant technical expertise. Azure benefits from familiarity within Microsoft-centric environments, while GCP keeps things straightforward with its declarative key management model.

Cost Considerations

Costs go beyond encryption fees. Businesses must also factor in key management, support plans, and operational overhead. For example, AWS support plans can cost up to approximately £11,500 per month, while GCP’s premium support starts at around £9,600 per month plus 4% of associated charges [39]. Using pricing calculators can help to estimate the total cost of ownership accurately.

Regulatory Compliance in the UK

UK organisations also need to consider the implications of the Data (Use and Access) Act 2025, which introduces updates to GDPR. Evaluating risks based on data sensitivity and the potential impact of breaches is critical [38].

For businesses looking to optimise their cloud costs while maintaining security, Hokstad Consulting offers tailored DevOps transformation services. They claim to help UK enterprises cut costs by 30–50% without compromising security.

Earning customer trust is the foundation of our business at AWS and we know you trust us to protect your most critical and sensitive assets: your data. [36]

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