CipherDrive™ does not need to load an entire large file into memory and then encrypt it as one enormous operation. Instead, the documented architecture can divide files into chunks and encrypt those chunks locally before upload.
This makes client-side encryption practical for files that are much larger than the amount of memory the browser should reasonably dedicate to one operation.
For a supported large-file upload, the conceptual process is:
You select the file.
Applicable pre-encryption safety checks may run.
The client generates a random key specifically for that file.
The file is divided into ordered chunks.
Each chunk is encrypted locally using the file key.
Each encrypted chunk is uploaded.
The file key is wrapped with higher-level vault key material.
Ackaia stores the encrypted chunks, encrypted key material, and necessary operational metadata.
The server does not need the plaintext file key to store the resulting ciphertext.
CipherDrive uses per-file keys rather than encrypting every file directly with one master key.
This provides useful separation:
a file has its own cryptographic key;
the master key can protect or wrap lower-level file keys;
sharing can be designed around individual objects;
key rotation, rewrapping, or selective access can be more flexible;
exposure of one file key does not automatically mean every other file uses that same key.
CipherDrive's documented cryptographic design uses AES-GCM for authenticated encryption.
AES-GCM provides two properties at the same time:
confidentiality: the plaintext cannot be read without the required key;
integrity/authentication: modified ciphertext should fail authentication during decryption instead of silently producing trusted output.
AES-GCM has an important security requirement: an initialization vector, or IV, must not be reused with the same key.
CipherDrive's documented chunking design conceptually builds a unique 96-bit IV for each chunk from:
a random 64-bit file nonce; and
a 32-bit chunk number.
Conceptually:
Chunk IV = random file nonce + chunk number
The random part differs between files, while the chunk number changes for each chunk in that file. This is designed to avoid IV reuse under the same file key.
Technical note: IV uniqueness is critical for AES-GCM security. Reusing an IV with the same key can seriously weaken confidentiality and integrity guarantees.
After client-side encryption, Ackaia receives encrypted chunk data rather than the readable file contents for ordinary encrypted storage.
Ackaia can still require operational information to store and reconstruct the encrypted object, enforce quotas, coordinate transfers, and maintain reliability.
This can include encrypted size, object identifiers, chunk or upload state, timestamps, account association, region placement, and other operational metadata.
The client performs the reverse operation:
CipherDrive verifies that the request is allowed.
The client obtains the encrypted file key and required cryptographic parameters.
The client unwraps the file key using the vault material available locally.
Encrypted chunks are downloaded.
Each chunk is authenticated and decrypted locally.
The client reconstructs the original file.
If a chunk has been corrupted or altered in a way that breaks its authenticated encryption, decryption should fail rather than treating the modified data as valid.
Chunking can provide several implementation benefits:
the entire file does not need to be held in memory at once;
encryption and network transfer can be processed in smaller units;
the architecture can support multipart or resumable upload workflows;
progress can be tracked across smaller pieces of the file;
download and decryption can also be streamed or reconstructed progressively by supported clients.
The presence of a chunked architecture does not mean every CipherDrive client or every operation guarantees automatic resume. Actual resume behavior depends on the current client implementation and service configuration.
Yes. Client-side encryption still depends on the device, browser, available memory, CPU, network connection, account limits, transfer limits, and service state.
A very large file may fail because:
the device cannot maintain the operation;
the browser process is terminated;
network connectivity is lost;
a plan or file-size limit applies;
storage capacity is insufficient;
a pre-encryption safety system blocks the upload;
the current client does not support the requested workflow.
The important privacy property is not simply that a file is “encrypted at rest.” It is that, for supported workflows, CipherDrive performs the content encryption in the user's client before ordinary encrypted storage, while Ackaia stores encrypted chunks and wrapped key material without ordinarily possessing the plaintext file key needed to read them.