Transaction signature Ed25519 or BLS12381 ?

[NabilNoaman]

Hi,

In https://developers.libra.org/docs/crates/crypto :

It is clearly mentioned that "Ed25519 to perform signatures. It is used both for consensus signatures and for transaction signatures."

But in current repo https://github.com/libra/libra/blob/master/crypto/nextgen_crypto/README.md we have :

Ed25519 performs signatures using the new API design based on ed25519-dalek library with additional security checks (e.g. for malleability).
BLS12381 performs signatures using the new API design based on threshold_crypto library.

I want to know which signature to be used for transaction signing Ed25519 or BLS12381 ?

Br,
Nabil

[asdgh1000]

Ed25519

[NabilNoaman]

Thanks asdgh1000.

So what is the usage of BLS12381 ? Is Libra association will use it in future for Tx signature ?

Br,
Nabil

[kchalkias]

Hi @NabilNoaman, Pure EdDSA Ed25519 is the sole scheme currently used either in consensus or transaction signing. The nextgen_crypto package was originally there to distinguish between current and future crypto primitives and BLS is one of the schemes we're evaluating, but it's not used yet. Future use depends on the results of our evaluation and discussions with the cryptography community, standardization progress etc.

But you made a good point, we will soon update the package structure and EdDSA will be moved from nextgen_crypto so the distinction is more clear.