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vabmit | 8 years ago
Currently, ProtonMail uses RSA keys, but this addition of ECC support to their web encryption library may mean that they are about to start switching users to ECC keys. Because using "larger" (when compared with equivalent theoretical strength RSA keys, for example) ECC keys is less resource intensive than using higher security keys in some other forms of cryptosystems (like RSA) it may also be an indication that ProtonMail is preparing to upgrade users to higher security/stronger keys.
Many cryptographers and organizations, including the US Government, have recommended for a long time that people migrate from older "big prime cryptography" based cryptosystems to ECC based cryptosystems for increased security.
chapill|8 years ago
Not what I've heard.
https://threatpost.com/nsas-divorce-from-ecc-causing-crypto-...
Shoothe|8 years ago
Personally I'd stay away from NIST recommended curves for long term keys (as used in OpenPGP). Ed25519 looks nice and there is experimental support for it in gnupg but it's not post quantum unfortunately.
dsacco|8 years ago
That's not a problem of NIST recommendations. There aren't any post-quantum secure elliptic curve public-key systems. The fundamental computational problem used by ECC public-key cryptography isn't post-quantum secure, so it's not really a matter of curve choice.
dsacco|8 years ago
Wow...I'm sort of shocked that wasn't a v1.0 consideration.
> ECC tends to be able to provide equivalent levels of security as traditional "big prime" cryptography (like RSA) with less computationally intensive operations. This is especially important in a library like OpenPGPjs that is primarily meant for in browser based web usage because it should make things, like sending and receiving mail, faster when ECC is used over older PGP public key encryption systems. For people that use ProtonMail's web based crypto on mobile or tablet devices, a switch to ECC would result not just in similar performance improvements but also in lower battery usage.
In particular, elliptic curves have smaller parameters, which allow for smaller keys at the same bit security level. For example, to achieve 128-bit security, an RSA/DLP modulus must be 3072 bits. Elliptic curves achieve the same security level with only 256-bit parameters. They are also faster for most operations, but RSA is still technically faster for signature verification.
> Many cryptographers and organizations, including the US Government, have recommended for a long time that people migrate from older "big prime cryptography" based cryptosystems to ECC based cryptosystems for increased security.
True, but elliptic curve cryptography is just as vulnerable to quantum computers, however long off that problem may be.
zahllos|8 years ago
Given that you need to pass --expert to gpg 2.1 as of right now to even generate an ECC keypair for PGP use (nor use one on an OpenPGP smartcard or yubikey), I can sort of forgive the lack of ECC in 1.0. I don't think it sees wide usage for PGP keys (some clients don't support it, also).
However, as of the last time I tried Protonmail (about 10 minutes ago to check this is all still true) you can't: revoke/reissue your PGP key, validate outside signatures (either on encrypted messages or signed, plaintext messages) or send pure-PGP mail to users outside of protonmail (there's an encrypt for non-protonmail users option, that sends a link instead). Essentially as another commenter has said, you can't really do PGP with ProtonMail.
wslh|8 years ago
My company contributed the ECC support for enabling messaging using the same keys as Bitcoin and other cryptocurrencies. See https://news.ycombinator.com/item?id=16548015
kfrzcode|8 years ago