Re: OT: how to securely produce a large data file for "one time tape" encryption input
- Posted by fizzpopsoft Aug 21, 2015
- 1767 views
Ok Jim I'll bite long enough to respond to your post.
If a PC bios is assumed hacked, then following Gregs advice earlier would make any data on the PC compromised. So, back to my idea. :)
The chips your links refer to, are not PIC chips; PIC chips have very limited capabilities and resources and its impossible to fit 4Gb into the intended PIC18F4550 chip. BTW, if some of the 256 bytes of PIC EEPROM was unusable(due to a hack resident), it would be noticeable, and could be overwritten anyway! If the 4Gb of random data is produced using said 48MHz PIC, and the XOR encryption and plaintext creation is also done on a PIC.. Then transfer via RS232 serial protocol only the encrypted file to your email capable PC.
The PC can never see the 4GB file or the plaintext.
Those files are stored on USB that only the PIC has access to. The PIC18F4550 chip is USB v2.0 capable, so speed is not an issue either.
Obviously I can look at the enciphered file on the PC before emailing to confirm its only the intended data transferred from the PIC.
