Crypto history for history buffs
 

Many knows about modern crypto tech like RSA and the names Whitfield Diffie and Martin Hellman are known to some, as they are celebrated as the ones who first figured out that public key crypto could work at all. Not many know that the British GCHQ were working on it a few years before Diffie had his eureka moment, and since the GCHQ was and still is pretty hush hush, names like James Ellis, Clifford Cocks and Malcolm Williamson are not near as well known.

Cocks was allowed to give a brief summary of their work in the 90's but I just found that 2 of Ellis' original papers have been declassified as well so for crypto history buffs, here is a link to one of the (technical) papers (2nd paper currently unavailable)

https://www.gchq.gov.uk/sites/defaul..._No_3006_0.pdf


Story with both links in it
http://aperiodical.com/2016/03/gchq-...-cryptography/

OTP is still ones of the prefered crypto means.

OTP is the holy grail in terms of security but for a large network, it becomes a logistical, economical and securitywise nightmare, something the Venona program showed. RSA and that branch of evolution is less secure but practical.

From a historical point of view, PKC is a monumental milestone as it proved one fundamental axiom of crypto wrong after more that 2600 years, that 2 people could securely share a secret without sharing the key.

Correct me if I am wrong, but isn't quantum crypto basically OTP equivalent?

QC in itself isn't OTP but QC is well suited for a OTP scheme. It is still being developed even though QC has been used, mainly in tests but also in short distance to medium distance transmissions. Long distance, especially between ground and satellite or through air for more than a short distance has proved tricky and is still researched. Right now the main selling point of QC, to my limited knowledge, is that evesdropping becomes impossible without leaving a mark (reportedly, this was shown to be possible under certain conditions not long ago but I don't have the actual report on that).

The main point though is, it was the RSA branch that gave us secure e-commerce, online bank transitions etc while the only other viable options until recently were symmetric key schemes.