Security in the cloud can be broadly categorized at the following three levels

• Infrastructure Security
• Application Security
• Data Security

Data Security

• Encrypt Data at rest and transit: cloud service provider providers mechanism to secure your data at rest and in transit. Encryption is one big tool in your arsenal, for example, a simple step of using HTTPS against HTTP will ensure your data is encrypted and secured while in transit. Similarly, most cloud service providers have encryption available for disks and databases to help secure the data.
• Data type-specific security: You also need to understand that there will be certain needs specific to the type of data you are storing, for example, if you are storing healthcare-related data, you will need to understand HIPAA (Health Insurance Portability & Accountability Act) needs, for finance-related data you might want to check PCI (Payment Card Industry) data standards. Also, there might be region-specific needs like in Europe we have GDPR or General Data Protection Regulation for personal data.
• Avoid Weak Encryption: Though most cloud service providers give us options to encrypt our data, filesystems, and disks, it is the responsibility of the architect to make sure strong encryption is implemented. Tools like Key Vault services can help to store encryption keys to avoid manual handling. Also, all your APIs and pages dealing with important data should use HTTPS (Secured) protocol.