cross-posted from: https://lemmy.ml/post/213192

The NSA intentionally weakened RSA through bribes; I imagine they will also attempt to gain control of quantum encryption.

  • Arthur BesseA
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    3 years ago

    [Prediction] The NSA will weaken standard quantum encryption to gain control. The NSA intentionally weakened RSA through bribes; I imagine they will also attempt to gain control of quantum encryption.

    There are a few points of confusion in this post.

    First of all, quantum cryptography - that is, using quantum mechanics for cryptographic purposes - is mostly not very interesting or important. There are a handful of companies selling products in this area, but it is mostly impractical and/or outright snake oil. The NSA doesn’t need to sabotage those.

    The important frontier in cryptographic research and development today is not quantum cryptography, but rather post-quantum cryptography - that is, creating cryptographic systems that will remain secure even if/when there exists a quantum computer capable of breaking the standard asymmetric primitives that the world relies on today (such as the RSA cryptosystem).

    This brings us to the next point of confusion: The NSA sabotages a lot of things, but I haven’t heard it seriously suggested that the RSA cryptosystem has had some secret weaknesses inserted. RSA does have two widely-known weaknesses, however: first, due to the advances in technology, attacking smaller RSA key sizes (eg 1024 bit) with classical (non-quantum) computers is no longer inconceivably expensive… it is still absurdly expensive, but could at least in theory be feasible (at enormous new expense for each key attacked). It’s probable that the NSA has taken some steps to discourage adoption of larger RSA key sizes, but, I haven’t seen any smoking gun to that effect, and most systems that were still using 1024 bit RSA keys have moved to larger keys over the last decade or so.

    The second big known weakness of RSA is that it can be trivially broken (using Shor’s algorithm) if a large enough quantum computer can ever be constructed. The defense against this is to design and deploy post-quantum cryptography. The NSA is almost certainly sabotaging this effort in a variety of ways because they hope to be able to build a quantum computer and deployment of PQC could thwart their ability to decrypt everything if/when that happens. This blog post from djb describes some of the impediments.

    Since you mention bribes, I assume you’re confusing the RSA cryptosystem (which is used by basically everyone today) with the Dual_EC_DRBG case where the NSA paid the company RSA Security (which makes software that is used by big companies, but is not used by the average person) to use the sabotaged Dual_EC_DRBG random number generator in their products.

    TLDR:

    1. “quantum cryptography” doesn’t matter; post-quantum cryptography is what is important
    2. the NSA probably didn’t weaken RSA (the cryptosystem) but is prolonging its use by sabotaging post-quantum cryptography