Anti-Exfil credited to Blockstream

Samson Mow's claim that the Anti-Exfil protocol originated at Blockstream, which he says wrote the first production-ready code for it, with a plain-language explanation that a dishonest hardware wallet can leak fragments of a private key through the nonces in its signatures until a chain observer can reassemble the key. He names Blockstream Jade and BitBox, which calls it Anti-Klepto, as the only two hardware wallets that implement it, credits Blockstream and Adam Back with protecting users since 2021, and quote-posts Blockstream Jade making the same point. Held as part of the record of competing vendors positioning themselves after the disclosure, alongside jade-not-affected and bitbox-not-affected, and because it concerns a different failure mode, nonce exfiltration at signing, from the seed-generation defect at issue in this incident. Interest: the poster is a former Blockstream executive and the post is a product claim for Blockstream's wallet. Replies to the post are restricted. The origination and implementation claims are the poster's own and are not verified here.