Dabih Documentation

Start using dabih

• Sign In to dabih. Account page
• Generate your keypair and upload the public key to dabih.
• Keep your private key in a safe location
• Wait for an admin to confirm your key.
• Upload and manage your data.

General Concepts

Encryption

• During file upload the dataset is processed in memory and not written to disk.

• When the upload starts the server generates a cryptographically strong pseudorandom AES-256-CBC Key (24 Bytes)

• The client creates “chunks”, sequential byte buffers of the data, each with size 2 MiB

• For each chunk we again generate a cryptographically strong pseudorandom initialisation vector (iv)

• The raw chunk data is hashed using SHA-256 and then encrypted using the AES key with the initialisation vector

• We then create a crc32 checksum of the encrypted chunk.

• This encrypted chunk is then written to the file system and the iv, hash and checksum written to the database.

• All the asymmetric keys are RSA Keypairs, with at least 4096 bits.

• We use RSA with Optimal Asymmetric Encryption Padding (OAEP).

• To prevent key exchange attacks all keys are fingerprinted using a SHA-256 hash.