Reliable file transfer?

[Victor Odhner]

Is there a file transfer protocol that will verify
the data as it comes across, and retry any failed
blocks?  Apparently sftp is not doing this.

I have a 1.5 GB .bz2 file on one computer that I am
trying to transfer to another nearby, via a local
router.  I don't have DVD drives.  (Both boxes have
USB ports, would that work better?)

In two attempts (30 minutes each), the number of
bytes received at least has been right.  But the
files arrive broken (according to bunzip2 -t) and
md5sum has given non-matching results.

The two wrong results have differed from each other,
so I will try once again . . .  Each try takes
30+ minutes.

Thanks,

Vic