Cryptography: just do not!

Software developers regularly attempt to create new encryption and hashing algorithms, usually to speed up things. There is only one answer one can give in this respect:

What part of "NO" don't you understand?

Here is a short summary of reasons why you should never meddle in cryptography.

  1. Cryptography is mathematics, very advanced mathematics
  2. There are only a few good cryptographers and cryptanalysts and even they get it wrong most of the time
  3. If you are not one of them, never, ever, ever try to write your own cryptographic routines
  4. Cryptography is a very delicate matter, worse than bomb defusing
  5. Consequently you must know that most usual “cryptographic” functions are not
  6. Even when it is good, cryptography is too easy to abuse without knowing it
  7. Bad cryptography looks the same as good cryptography. You will not know whether cryptography is broken until it is too late

So, I hope you are sufficiently convinced not to create your own cryptographic algorithms and functions. But we still have to use the cryptographic functions and that is no picknick either. What can mere mortals do to keep themselves on the safe side?

Additional information:

Supply chain: Huawei and ZTE

United States House of Representatives Seal

US House of Representatives published an interesting report about their concerns with Huawei and ZTE, large Chinese telecom equipment providers. The report states openly that there are concerns that the equipment, parts and software may be manipulated by the Chinese government agencies, or on their behalf, in order to conduct military, state and business intelligence. The investigation that the report is the outcome of did not dispel those concerns but made them more founded, if anything. We have to keep in mind that this is a highly political issue, of course. But even then, citing such concerns underlines what we talked about for several years now: the supply chain is a really important part of your product’s security and blindly outsourcing things anywhere is a security risk.

The Elderwood Report

Symantec reports very interesting findings in their report of the so-called “Elderwood Project”. A highly interesting paper that I can recommend as bedside reading. Here is a teaser:

In 2009, Google was attacked by a group using the Hydraq (Aurora) Trojan horse. Symantec has monitored this group’s activities for the last three years as they have consistently targeted a number of industries. Interesting highlights in their method of operations include: the use of seemingly an unlimited number of zero-day exploits, attacks on supply chain manufacturers who service the target organization, and a shift to “watering hole” attacks (compromising certain websites likely to be visited by the target organization). The targeted industry sectors include, but are not restricted to; defense, various defense supply chain manufacturers, human rights and non-governmental organizations (NGOs), and IT service providers.

SHA-3 is there!

NIST has announced the end of the Secure Hash Algorithm competition the day before yesterday, naming Keccak as the winner and making it the SHA-3 algorithm. The complete announcement from NIST is here.

One thing of note is that since the algorithm was developed by STMicroelectronics and NXP Semiconductors, the algorithm is heavily optimized for the use in smart cards. According to the announcements, it is both compact and fast when implemented in hardware. Which makes it once again very well suited to some applications and difficult to use for others (like password hashing).