Abstract: A scheme for securely transferring a patient data file to an intended recipient regardless of a transfer mode selected by a sender. Encryption system executing at the sender device is operative to encrypt each plaintext data line of a file, one by one, using a symmetric key and a starting IV that is incremented per each line, resulting in corresponding ciphertext lines added to an encrypted file. A hash is generated based on the encrypted file. An encrypted header containing the symmetric key, starting IV and the hash is generated using a public key of the recipient, which is appended to the encrypted file. The encrypted header and associated encrypted file are transmitted to the recipient in any manner. Upon receipt, the recipient decrypts the encrypted header using a private key to obtain the symmetric key, starting IV and the hash, which are used by the recipient to validate and decrypt the encrypted file on a line-by-line basis.