@li0ard

Fullstack TS developer, cryptography enthusiast, connoisseur of coffee Github: @li0ard

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li0ard.rest
Joined August 2024
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Messenger @session_app in new Blinded ID algorithm makes same mistake as in old algorithm. Again failed if-condition is used to check sign bit (key[31] & 0x80) to generate hash of the server's public key, as result we again have 2 variants of possible public key when converting.
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Remarkably, Signal had same problem when developing the XEdDSA and VXEdDSA algorithms, but they solved it by forcibly zeroing the sign bit. signal.org/docs/specificatio… P.S I especially like that "libsession-util" repository intentionally disables issues

Specifications >> The XEdDSA and VXEdDSA Signature Schemes

This document describes how to create and verify EdDSA-compatible signatures using public key and private key formats initially defined for the X25519 and X448 elliptic curve Diffie-Hellman functions.

signal.org
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Blinded IDs in @session_app are reversible, which creates the possibility of obtaining the real user ID, and effectively "kills" privacy in public chats . The picture shows a sample recording of the vulnerability algorithm
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Verifying my account on nostr My Public Key: "npub1f8jkdgm92km2v6ynax4n5k85ljjf8w0k8vwh29vydghpzzezc0rspg8v6f"
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