Falcon – ECDSA and Ed25519 replacement with post-quantum ring signatures | Hacker News Reader

Falcon – ECDSA and Ed25519 replacement with post-quantum ring signatures

falcon-sign.info

21 pointscapableweb10 comments

5x faster, but public keys are 900 bytes, more than 3x that of RSA, and way bigger that ed25519's 32 bytes.

If this becomes popular, I'll miss my short "authorized_keys" lines.

A small price to pay for inconvenience hahaha

Could be worse. I read a paper that proposed a functional encryption scheme for functions with a single 64-bit input. The ciphertext was several gigs.

Just curious, why no 256?

I wish the PoC of these were written in Go or Rust so they could be built without weird hacks or dependencies.

Having both Python (https://github.com/tprest/falcon.py) and C (https://falcon-sign.info/impl/README.txt.html) seems good enough for a PoC. Usually you only get one implementation :)

C is great because almost every language, Go and Rust included, has well supported FFI interface for it, and because it has no runtime requirements.

This particular library doesn't even use memory allocation, which is great for things like embedded, OS-less hardware. This would be impossible in Go, and will require non-ideomatic Rust.

Zero-allocation Rust is quite idiomatic. I write some every day :)

Maybe "not ideomatic" is not quite the right word... They are explicitly making their API more complex in order to support unusual usages. They avoid heap allocation by making user pre-allocate output buffers. And they even avoid stack allocation by having user provide "void* tmp" argument (see [0]).

One can definitely implement such interface in Rust, but I don't think it would be pleasant to use. Having to worry about temp buffer allocation at most calls is not something one wants to do.

I am pretty sure that this library is designed to be wrapped by a second layer -- be it in Rust, C++ or even GLib-style C.

[0] https://falcon-sign.info/impl/falcon.h.html

Taking a mutable slice is extremely common for exactly this reason. Even in the standard library, which can allocate. We added some convenient functions later, but it's a pretty standard practice.

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