Here is a summary of the blog post in full sentences:

The blog post discusses cloud data encryption using AWS Key Management Service (KMS). It first defines some key terminology: encryption converts plaintext data into ciphertext using an algorithm and key, and KMS allows you to manage encryption keys and encrypt/decrypt data. The steps covered in the post include: creating a custom KMS encryption key; generating random plaintext key material locally with OpenSSL; encrypting the key material with the KMS wrapping key and uploading it to AWS; using the KMS key to encrypt and decrypt a text file from the command line; deleting and reimporting the key material to demonstrate how it removes the ability to decrypt data; and using envelope encryption where a data key is generated by KMS, used to encrypt data externally, and can later be decrypted by KMS. Envelope encryption is useful for overcoming limits on size and latency when encrypting directly with KMS. In summary, the post demonstrates some core KMS encryption features using custom key material, but does not cover other options for AWS-managed or external key stores, key management/auditing,