• Security is quality under attack. Hard-won lessons in software security, from someone who built the programs and wrote the standards.

Technology

Hack NFC Door Locks

I can see in the logs that people sometimes come to this site with interesting searches. A recent interesting search was “Hack NFC Door Locks”. Well, since there is interest in the subject, why not? Let’s talk about NFC, contactless smart card and RFID door locks, shall we not? The actual technology used for the ...

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

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: Here is a short summary of reasons why you should never meddle in cryptography. Cryptography is mathematics, very advanced mathematics There are only a few good cryptographers and ...

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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 ...

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Random or not? That is the question!

Oftentimes, the first cryptography related question you come across while designing a system is the question of random numbers. We need some random numbers in many places when developing web applications: identifiers, tokens, passwords etc. all need to be somewhat unpredictable. The question is, how unpredictable should they be? In other words, what should be ...

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NFC, ain’t that funny

When we invented NFC (Near Field Communication) we never intended it for some of the uses that it was put to afterwards. And when we started discussing those unconventional (for us) uses, we immediately pointed out all security problems and proposed methods to protect the NFC devices from various attacks. That was… probably 2004. Do ...

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Password storage in summary

We discussed the password storage in the article Speaking of passwords…and concluded that password implementation requires a cryptographically strong, contemporary (as in “very, very slow”) one-way hash function with a randomly generated salt for every password. This is pretty much all you need to take care of. Salting is fairly straight-forward but it is essential to ...

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News: Website and app security tips

TechRepublic has an interesting article “Website and app security tips for software developers” that talks in a very short space about a whole bunch of things, from the “shelf life of software developers” to the advice on security for the website developer. It provides in particular an interesting insight into why a person thoroughly familiar ...

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Speaking of passwords…

Wouldn’t it be quite logical to talk about passwords after user names? Most certainly. Trouble is, the subject is very, very large. Creating, storing, transmitting, verifying, updating, recovering, wiping… Did I get all of it? It is going to take a while to get through all of that, do you reckon? Let’s split the subject ...

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Biometrics – any good?

I think I already talked about this subject previously but not here. Anyhow, the subject bears repeating. Many go “yippee!” at the mention of biometrics and start to think their user authentication problem is solved. Do not pay attention, they will end up in the newspaper headlines fairly soon, either for massive security failures or ...

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Keep it simple – user names

All right, now after the lengthy discussion on user names and ids let’s have some simple rules: Do not use sequential numbers for user ids. Do use random numbers for user ids. Do not use any scheme for user names that ties (semi-)public user information to the user name. Use user nicknames (aliases) if “natural” ...

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