Fig. 2From: A protocol for a multi-site, spatially-referenced household survey in slum settings: methods for access, sampling frame construction, sampling, and field data collectionData flows: (1) Validated field data are encrypted, submitted to the cloud server, and deleted from the tablet device. (2) Encrypted data are sent via SFTP to an internal storage server. (3) Data are downloaded, decrypted, for checking. (4) Processed data are re-encrypted and re-uploaded. (5) Authorised external users can download and decrypt the data. Key symbol represents encryption/decryptionBack to article page