Post-Mortem: What Happened Between Samourai Wallet and Me

How a wallet that adopted my privacy framework turned technical disagreement into a reputational war—and what I got wrong too

After law enforcement seized Samourai Wallet’s servers, William Hill—TDevD—messaged an associate: “Not good.” Then he named the thing that worried him: “I’m not thinking so much about Whirlpool as I am about the wallet backends (xpubs).”³³

An extended public key cannot spend a user’s bitcoin, but it can reveal the addresses derived from a wallet and follow their history. For years, I had argued that Samourai’s default backend created exactly this point of failure. Hill’s message showed that he understood why the seizure of that backend mattered.

The government’s sentencing memorandum records Hill’s post-seizure message: “Not good,” followed by his concern about “the wallet backends (xpubs).” Open the archived filing.

The seizure did not create the xpub problem. It exposed the consequences of a design choice that had been there from the start.

I do not offer this post-mortem as vindication. A prison sentence cannot settle a protocol dispute, and an indictment cannot make every allegation true. I will distinguish what the public record establishes, what I infer from it, and what I remember but cannot independently prove.

To understand what was sitting on that server—and why I had spent years shouting about it—we have to go back to a README file in July 2017, before the feud began.

How ZeroLink actually began

I wanted Samourai to succeed in implementing ZeroLink. I wanted more wallets to implement serious Bitcoin privacy, and I wanted ZeroLink to become useful software rather than another specification admired by a small circle and ignored by everyone else.

I created ZeroLink. The repository makes the chronology clear. I opened it on July 28, 2017. Before Samourai made a single commit, I had made 19 and written a 184-line, 2,883-word document containing the framework’s core architecture. Samourai’s first commit arrived two days later. Its title was “Fix typos”. It did exactly that.

ZeroLink was not merely a name for a CoinJoin transaction. It was a privacy framework for Bitcoin wallets: blinded coordination together with rules for network privacy, coin selection, transaction chains, and spending after the mix. I described that scope plainly in a 2021 Wasabi Research Club discussion: Chaumian CoinJoin was the protocol; ZeroLink was the broader wallet framework. That is the work Samourai later claimed to have co-created.¹

SamouraiDev’s first ZeroLink commit, July 30, 2017: “Fix typos.” Open the commit.

At the August 14 publication snapshot, Git blame attributes 6,126 of the document’s 6,627 words to me and 242 to Bill/TDevD. Their only sizeable technical addition concerned BIP47 and stealth addresses. I did not understand what problem it solved or why it belonged in ZeroLink. Instead of challenging it, I assumed that I was missing something and accepted it out of politeness. Two days later I clarified that BIP47 was not part of the protocol, and I removed the section in 2019. The rest of their work was overwhelmingly light editing. The complete commit and line-churn audit is preserved in the source note.¹

I had also put TDevD in the Authors section before the BIP47 proposal was committed. Both decisions came from the same reflex: they spoke with confidence, I assumed that any confusion was mine, and I tried to be generous. Their confidence made me doubt my own judgment, while my politeness was later used to support a claim of authorship that the repository does not support.

By 2022—three years after I had publicly challenged the joint-creation claim, with the Git history still open for anyone to inspect—Samourai was still repeating it.²⁵

I regard those later repetitions as a lie. “Collaboration” can be innocent shorthand while nobody has disputed it. It stops being innocent after the primary record is placed in front of you and you keep telling the version that promotes you from reviewer and prospective implementer to co-creator. The false version gave Samourai ownership of the intellectual foundation it had adopted and made my later objections sound like jealousy over something we had supposedly invented together.

Our contact was limited. We barely spoke, and I was never part of Samourai. I had created ZeroLink; Samourai said it intended to implement it. Brian “Shinobi” Trollz, who observed the dispute at the time, later recalled a specific turning point. I asked for a week to consider whether coordinators could be run altruistically. During that week, he said, Samourai’s posture toward me shifted into mockery. By April 2019, I had recorded that they were no longer interested or responsive and that I had continued independently. People can disagree about why that limited contact ended. The authorship record is not a matter of recollection.

The authorship dispute mattered to me, but the architectural difference between the wallets affected users directly.

The central privacy difference

The two wallets exposed users to very different risks from their service operators.

Wasabi’s default architecture was built to deny its own operator the wallet graph. The backend distributed block filters; clients checked addresses locally; wallet traffic went through Tor; and blinded CoinJoin credentials prevented the coordinator from linking a registered input to its output. A user did not need to operate a personal server to hide addresses and transaction history from us. Privacy from the service operator was the default.²

Samourai’s default client sent extended public keys to Samourai’s hosted backend. Whoever holds an xpub can derive its associated addresses and follow their transactions. Samourai’s own Dojo documentation disclosed the consequence indirectly. Running MyDojo improved privacy by “completely bypassing” the default hosted servers, while its Tracker recorded registered xpubs and addresses.²

Then came the clearest lie in the xpub argument. In October 2022, Kruw said that the default app exposed the user’s xpub and asked why Samourai would not use BIP157/BIP158 client-side filters. The official wallet account refused, said it had chosen “the best architecture for our needs,” and soon afterward claimed it had been “open and truthful from day one.” When asked whether wider BIP157 adoption would change its decision, it answered: “We are a full node wallet. Always have been.”³

That was false. The Android app was a light client of a backing server. Dojo could put that server and the Bitcoin Core node behind it under the user’s control, but it did not turn the phone into a full node. Samourai’s own 2019 announcement said default users had to trust its servers with their public keys. Hill’s sentencing submission later described the affected architecture as one used by “light wallets.”³

Four posts from the October 3 exchange, in chronological order: the default xpub disclosure is raised; Samourai defends its chosen architecture; a user asks whether wider BIP157 adoption would change the decision; and Samourai falsely calls the Android app a full-node wallet. Open the final reply.

Tor support existed, but it was not enabled by default. Samourai’s signed source allowed a user to create a wallet while Tor remained off, treated the Tor preference as false unless the user enabled it, and used the ordinary network path for xpub requests when Tor was disabled. A screenshot preserved in an April 2023 issue on Samourai’s own GitLab showed the wallet-creation screen with both Tor off and Dojo unconfigured. The user could continue by pressing “Create a new wallet.” That default exposed the user’s IP address to Samourai’s hosted service while the same service received the wallet’s xpubs.¹⁵

The wallet-creation screen attached to Samourai’s own issue tracker: Tor off, Dojo not configured, and “Create a new wallet” still available. Open the archived issue.

The issue was titled “Important privacy features are disabled by default.” It proposed enabling Tor and Dojo by default or, at minimum, warning users what the off settings exposed. A Samourai project owner replied that the proposal would not be merged, called the report “concern trolling,” issued a “first and final warning,” and immediately closed the issue.¹⁵ The privacy problem was reported on their own development platform. Their answer was to reject the change and threaten the person who reported it.

The October claim followed an earlier evasion. In July 2022, a user wrote: “Xpub is sent to whirlpool servers.” Hill answered by changing the noun: “No xpubs are handled by the coordinator.” The xpubs went to Samourai’s wallet backend, not the Whirlpool coordinator. He also claimed that Samourai had implemented ZeroLink “on spec,” something I supposedly “didn’t have the skill set to do.” The reply avoided the backend issue and falsely reversed the authorship record.¹⁴

Sentinel, Samourai’s watch-only app, made the same architecture even easier to see. A watch-only wallet legitimately needs an xpub, and Sentinel correctly said that it could not spend the user’s coins. But the privacy question was what happened to the xpub after the user imported it. In August 2017, Samourai committed a change titled “move XPUB multiaddr to Samourai API.” From then on, Sentinel sent each tracked xpub to Samourai’s hosted backend. It did so for more than two years before Tor routing was added; when Tor arrived, its preference defaulted to off. The last pre-seizure source still let a user choose Samourai’s server, answer “No” to “Connect through Tor?”, and then posted imported xpubs to that server.¹⁶ Sentinel could not spend users’ coins, but its hosted mode let Samourai map their wallets. That collection was integral to the product rather than incidental telemetry.

The Sentinel commit that moved XPUB multiaddr queries to Samourai’s API. Open the commit.

William led the Blockchain.info Android wallet project that preceded Samourai. He opened the surviving Android-Wallet-2-App history with its April 2014 initial commit and is its dominant visible developer by commit count. His own sentencing submission calls him Blockchain.com’s senior mobile developer; contemporary coverage identifies Keonne as the product lead responsible for the refreshed wallet’s interface and user experience. William’s commits even include “UI prep for shared coin,” Blockchain.info’s earlier mixing product. They did not create Blockchain.info itself, but they led the mobile-wallet project from which Samourai emerged.⁵

Samourai then kept its own source private for about a year. At the time, it said the delay was deliberate and intended to give the product a competitive “leg-up.” When the first public Samourai snapshot finally appeared in March 2016, it contained unmistakable Blockchain.info lineage: among other examples, its BitcoinScript, BitcoinAddress, Hash, and swipe-listener files descend closely from the earlier wallet. The lineage does not make the entire codebase a copy, but it contradicts the image of a clean-sheet privacy wallet appearing from nowhere.⁵

SharedCoin matters because the old trust model was already understood. It was non-custodial, but its server constructed the joins and knew their links. In two Research Club discussions, participants treated that server knowledge as obvious: public transaction ambiguity could not provide privacy from the operator that already knew the mapping. When a 2021 paper named that weakness in SharedCoin but omitted Samourai’s default xpub collection, I objected. The products used different mechanisms, but the operator occupied the same privileged position. Samourai had rebuilt the problem it claimed to have left behind.⁶

Dojo did not change what the default client disclosed. Most users of a mobile wallet will use the default, and even people who ran Dojo entered Whirlpool rounds alongside default-server users. If the common operator could identify or eliminate the outputs belonging to wallets it already knew, the effective anonymity set shrank for everyone; in some rounds, the remaining participants could be exposed by exclusion.¹⁹

None of this is hindsight invented after the servers were seized. In an April 2020 Wasabi Research Club presentation about ZeroLink, I described the rejected design plainly: a trusted central server to which everyone sends their xpubs. That, I said, “obviously sounds pretty stupid,” which is why ZeroLink used blinded coordination instead. In July 2021, while reviewing a paper that contrasted Blockchain.info’s SharedCoin with Samourai, I objected that the comparison omitted the decisive fact: Samourai also learned wallet relationships because its default server collected xpubs. If the server has the xpub, repeated mixing cannot erase what the server already knows; and Dojo users still share rounds with users known to that server. In September 2022, discussing balance-query architectures, I warned that any other computer retaining an xpub could later be hacked or seized. The government seized Samourai’s servers in April 2024.⁶

The practical distinction was whether the operator was prevented from learning wallet relationships or merely trusted not to use them.

Wasabi was not perfect against every imaginable adversary. No honest system built on Bitcoin, Tor, fallible software, and human behavior can promise perfection. But against the service operator—the adversary at the center of this dispute—Wasabi placed cryptography and local processing between the user and us. Samourai relied on trust in its operator.

Samourai preached resistance to third-party surveillance while ordinary users entrusted it with a durable view of their wallets. When developers pointed out the contradiction, the honest response would have been simple: our default server receives your xpub; if that threat matters to you, run Dojo. Instead, Samourai attacked the people who explained the trust assumption.

Sockpuppets and attacks on critics

My first SamouraiLeaks investigation began with a suspicion: one of Samourai’s developers appeared to be promoting the project and attacking its critics through an identity presented as independent.

In April 2019, I published the evidence that “foneBTC” and “fone-btc” were TDevD/William Hill’s sockpuppet accounts. The investigation is the proof. Its concluding exhibits are preserved below so the record does not depend on Medium remaining online.

But the moral question does not turn on whether Bitcoin developers use pseudonyms. Pseudonyms are normal here. The problem is hidden affiliation used to manufacture consensus: one participant appearing to be several, promotion made to look organic, and an interested party presenting himself as a neutral observer. In a field where few users can audit every cryptographic claim themselves, reputation becomes part of the security model. Astroturfing corrupts that model.

Before publishing, I tried private conversation, sought a mediator, and offered to stop discussing Samourai if the attacks stopped. I eventually concluded that my silence was being treated as permission rather than de-escalation.

Other developers then began describing the same experience.

Gregory Maxwell said architectural criticism was answered with harassment and accusations rather than a technical response. Nicolas Dorier reported the same reaction after pointing out that the default backend received users’ extended public keys. Their comments remain in the original discussion, including Dorier’s account. Luke Dashjr said that disclosing an RPC-password exposure in a setup guide brought an accusation that he ran a criminal protection racket; his own qualification—that local networking or a VPN could limit the exposure—remains in the thread. I gathered those and similar accounts in SamouraiLeaks Part 2.

They were independent developers, not a Wasabi group, and several had also criticized Wasabi. Their accounts described the same response: technical objections were redirected toward the critic’s motives, status, or character.

Chris Belcher later described substantive BIP47 objections being answered by smears against the people raising them. ZmnSCPxj said Samourai had misrepresented his technical comments and again emphasized the privacy cost of the default server.²⁰ A JoinMarket contributor acknowledged that individual criticisms on both sides could be valid while identifying Samourai’s counterattacks as the reason productive discussion became so difficult.²¹

Accuse loudly, qualify quietly

After enough repetitions, the sequence became predictable: start with something real—an uncertainty, a compromise, or a bug—then attach the most damaging interpretation available and promote it until it becomes the headline. When contrary evidence arrives, place the qualification where fewer people will see it: inside a reply, outside a screenshot, or silently inside a later code change.

The claim that I had admitted Wasabi supplied its own liquidity followed this pattern. I had made no such admission. The journalist responsible for the report corrected the characterization, but the correction never travelled as far as the accusation. Another observer documented how Samourai’s presentation excluded my correction and contrary replies.

A cropped account can be misleading even when every visible fragment is genuine, because the omitted context changes its meaning.

The same technique appeared elsewhere. In 2023, Samourai circulated criticism from Matt Corallo while omitting his concluding post. BlockDigest documented a smaller but revealing PayNym episode: a question about short-name mappings drew insults and brigading, and the issue was later patched without the public acknowledgment that would have turned a quarrel into routine engineering.²²

The Tor identity dispute provides another example. In April 2023, a user asked whether Whirlpool changed Tor circuits between input registration and output registration. Keonne Rodriguez answered categorically that it did and dismissed the questioner as a known liar.²³ In March 2024, the Whirlpool client added an explicit changeIdentity() call before output registration. The code comment explained that the new identity was used to unlink the output from the input.

April 2023: Rodriguez answered that the coordinator used new Tor circuits regardless of the client’s Tor settings and called the questioner a liar.

March 2024: the client added changeIdentity() immediately before output registration, with the comment “use new identity to unlink from input.” Open the commit.

The later commit cannot establish whether earlier Whirlpool rounds were deanonymized or whether anyone exploited the behavior. It does establish that the categorical denial was unsafe. A precise answer in 2023 would have explained what the client did, what had been verified, and what remained uncertain. Rodriguez instead answered with certainty and an insult; the code changed later.

This response culture encouraged users to treat disclosures as tribal attacks and raised the social cost of reporting problems. Even small bugs became hard to discuss because the reporter risked becoming the subject.²²

Accusations presented as security research could damage Wasabi without demonstrating a break.

The OXT “critical vulnerability” that failed its own test

OXT was not an independent research group that happened to agree with Samourai. In December 2017, Samourai announced that it had “finalized the acquisition” of OXT in an all-bitcoin transaction and called it a long-term strategic investment. OXT would remain a separate entity, the announcement said, but one “complementary” to Samourai. Years later, an OXT developer’s support letter included in William’s own sentencing submission described OXT as a Bitcoin forensic tool “owned and operated by Samourai Wallet.” The government separately noted that William and Keonne operated OXT as a tracing and wallet-attribution tool.⁸

An OXT developer’s letter in William’s sentencing submission describes OXT as a forensic tool “owned and operated by Samourai Wallet.” Open the archived filing.

We did not reject OXT’s work because it came from a rival. In March 2020, five months before OXT’s ultimatum, the Wasabi Research Club devoted an entire session to LaurentMT’s Boltzmann—the transaction-analysis tool Samourai’s own acquisition announcement had praised. We examined how it counted possible transaction partitions and where that number stopped being a measure of an individual user’s privacy. A high transaction-wide entropy score does not include everything a targeted observer may know from the network or the wider transaction graph, and computing all partitions becomes impractical for large Wasabi transactions. We engaged with the work in public before OXT attacked us. We rejected the later “critical vulnerability” because its premises failed.¹¹

In August 2020, this Samourai-owned research arm announced two supposed Wasabi vulnerabilities, rated them High/Critical, claimed they could cancel the privacy gained from earlier mixes, and gave us forty-eight hours to publish a warning on their terms. The full report contained a fatal premise: the attacker had to know the composition of the target’s wallet at a chosen point in time and know events affecting the wallet’s participation in later rounds. That was not a minor condition. It supplied the wallet membership that the alleged attack was supposed to uncover.²⁴⁸

OXT avoided that problem in its demonstration by controlling both sides. Its target, “Alice,” received one known 0.4 BTC coin. Its observer, “Eve,” already knew which funds belonged to Alice and ran a modified Wasabi client that logged round events. Given the wallet’s exact starting state, the public coin-selection code could sometimes predict which of Alice’s coins the client would offer next. That showed that known software can behave predictably when the observer is handed its private starting state. It did not show how an outside observer could discover an unknown wallet’s contents, identify an unknown mixed output as the target’s, or recover an input-to-output link hidden by the protocol.²⁴

Even in that constructed test, the predictions did not simply work. The report recorded expected coins failing to enter rounds because of confirmation state, failed rounds, and coordinator behavior. OXT called these deviations “exogenous randomness.” Its second “vulnerability” was a proposed use of change-output “beacons and checkpoints” to notice when the first prediction had failed and investigate why. The report’s reduced “adjusted anonsets” were values produced by OXT’s own model. They were not identities uncovered, owners identified, or blinded input-output links recovered.²⁴

OXT’s follow-up speculated that a powerful adversary might possess exchange data, pooled surveillance information, or coordinator logs, but it never demonstrated how the attack would acquire the wallet state it required. My contemporaneous line-by-line response made the distinction: the report assumed near-complete knowledge of the target wallet; its conclusion that prior mixes were “cancelled” did not follow from that assumption; and OXT’s own spreadsheet had failed to predict the exact coins selected in its own wallet.²⁴

Adding randomness can be reasonable hardening without validating a claimed exploit. Samourai later treated Wasabi 2’s different selection behavior as an admission that OXT had been right.²⁵ The timeline disproves that story. We established the Wasabi 2 research effort in January 2020 and publicly presented WabiSabi in June, before OXT’s August disclosure. Wasabi 2 was an already-planned replacement of the CoinJoin protocol and user experience, not a patch accepting OXT’s conclusions.²⁴

OXT’s hypothetical Wasabi attacker needed to begin with a target’s wallet map, while Samourai’s real default backend collected wallet maps. OXT’s own follow-up declared that privacy guarantees must come from “default software behavior,” not from placing the burden on the user. Samourai’s default failed that standard; its users had to run Dojo to escape the hosted server that OXT’s owner operated.⁸

The trap of criminal association

The OXT report was part of a broader tactic. Samourai and OXT repeatedly attached Wasabi’s name to alleged criminal activity, then treated the association itself as evidence against us. The trap worked either way. If we answered, we helped spread the association. If we stayed silent, they presented the silence as a concession.

In several instances we never had a safe opportunity to answer. A meaningful response would have required disclosing operational knowledge, investigative methods, or decisions that could not be made public without compromising opsec. Some claims therefore circulated largely unchallenged. The absence of a public response reflected that constraint, not agreement.

Samourai made that double standard explicit after Luke Dashjr’s theft. On January 4, 2023, OXTObserver flagged 204.77460928 BTC under #LUKE-JR_STOLEN_FUNDS and described the wallet as controlled by hackers. Samourai Wallet quoted the alert as “Luke-jr stolen coins on the move.” When a user asked what Samourai would do if the thieves tried to mix the coins in Whirlpool, the official account answered: “If they go into Whirlpool? Relish in the delicious irony and extra salt in Luke’s gaping wound.” The exchange does not show that the coins entered Whirlpool. It shows the official account expressing pleasure at the possibility because the victim was Luke.⁹

I cannot draw a straight causal line from one Samourai post to one institutional decision. I can say what followed: exchanges scrutinized Wasabi CoinJoin deposits, journalists carried the criminal-association narrative outward, and legal and regulatory pressure on the company increased. By 2022, the survival of the company-run coordination service was in question.

The default zkSNACKs coordinator then began rejecting some UTXOs. I had argued against blacklisting, and people who felt betrayed had a legitimate grievance. The policy was censorship by one service, but it did not reveal the relationship between accepted inputs and their outputs. The protocol still blinded that relationship; Wasabi remained MIT-licensed; and other coordinators could run without zkSNACKs’ policy.²⁶

Samourai converted that policy dispute into the claim that Wasabi had become a surveillance wallet. The comparison ignored the relevant architectures: zkSNACKs refused some inputs without learning their outputs, while Samourai’s default backend received and retained ordinary users’ wallet maps.

The megaphone was bigger than the product

Samourai’s Twitter presence made the rivalry look symmetrical despite the large difference in usage. Dumplings—my reproducible CoinJoin scanner—separated fresh bitcoin entering a mixer from coins merely being remixed and called fresh bitcoin the best on-chain proxy for adoption. From Whirlpool’s first detected month in April 2019 through the dataset’s end in August 2022, it identified 247,675 fresh BTC entering Wasabi and 30,228 entering Whirlpool. Wasabi led in every one of those forty-one months. This is a measure of bitcoin, not a user headcount, but it is the opposite of adoption parity.⁷

Dumplings’ original “Fresh Bitcoins CoinJoined” chart. Wasabi is green; Whirlpool—labelled “Samuri” in the scanner—is red. The chart shown runs through November 2021; the archived data continues through August 2022. Open the reproducible scanner.

Whirlpool’s headline transaction totals were enlarged by free remixes: the same bitcoin could appear in round after round without representing a new user or newly arriving funds. Samourai’s much larger Twitter presence made the products look more evenly adopted than the Dumplings data supported.

OXT’s report gave a marketing attack the appearance of a vulnerability disclosure through a technical PDF, severe labels, a deadline, and claims of immediate danger. Its demonstration showed predictable code only after the observer was given the information the protocol was designed to hide.

Moving the problem did not solve it

Whirlpool’s strongest design slogan was that its CoinJoin transactions contained no toxic change. TX0 kept the change out of the CoinJoin transaction and placed it in a separate account so users would be less likely to spend it with mixed coins, but the toxic change still existed. Samourai itself later called these coins “unmixed toxic change” while proposing a way to swap them into Monero.¹²

The same TX0 publicly joined the deposit inputs, created the fixed-denomination premix outputs, and exposed which first Whirlpool rounds spent them. In a 2023 Research Club panel, a participant compared this directly with Wasabi 1 and made the narrow point that peeling change off before the CoinJoin did not create an additional break between that change and the first mix. It moved the point at which the change appeared.¹²

Fixed denominations created another cost at both ends. A user could have to combine inputs publicly in TX0 to enter a pool. Later, an ordinary payment would rarely equal one pool denomination, so the user could have to combine multiple post-mix outputs and create new change. The official Whirlpool server configuration enforced those denominations. Equal-output CoinJoins still provided privacy, but the clean CoinJoin transaction was only one part of the user journey, and remix counts could not show whether that privacy survived the eventual spend.¹²

Ricochet had the same gap between a useful trick and a sweeping privacy impression. Its source built a default four-hop chain in which each transaction spent the previous one and reduced the forwarded amount by a calculated per-hop fee. That could frustrate a crude system that looked back only a fixed number of transactions. It also produced a recognizable shape. The Research Club flagged the unique fingerprint in 2020 but deferred a full analysis, so the source supports only the narrower conclusion that Ricochet’s marketing certainty was not earned.¹³

Security claims require precision

The archive contains well-supported findings, ambiguous claims, and some historical mislabeling. They should not be treated as one undifferentiated charge sheet.

In 2021, an independent researcher disclosed a real local PIN-bypass weakness in Samourai Wallet. Restarting the app reset the attempt counter; wallet metadata required for an offline PIN search was available on the device; and the PIN space was small. The issue became CVE-2021-36689. According to the researcher’s timeline, Samourai acknowledged the report and initially decided not to fix it before public disclosure.²⁷

That is a legitimate security failure with a defined version and threat model. It concerned a local attack, not the remote draining of every Samourai wallet.

My SamouraiLeaks Part 3 investigation concerned a different and earlier codebase: the Blockchain.info Android wallet project William led as senior mobile developer while Keonne served as product lead. The visible repository begins with William’s initial commit and attributes more commits to him than to any other developer. That history tied him to a generator that fetched entropy from Random.org over unencrypted HTTP. Under a narrow fallback path on older Android devices, a redirect combined with failed local entropy could produce deterministic key material.²⁸⁵ Ars Technica independently reported the conditions and risk in 2015.²⁹

That history documents a serious engineering failure under specific conditions. It does not support claims that every Samourai wallet used broken randomness or that William stole anyone’s coins.

Those limits are essential to responsible disclosure, which requires defining what happened, who was affected, what is inferred, and what remains unknown. Samourai’s communications culture treated those distinctions as weakness when answering critics, then demanded endless qualification when scrutiny turned inward.

The official account made the imbalance visible. It responded to technical and community critics with obscenities, slurs, and personal humiliation.³⁰ A former r/Bitcoin moderator preserved his allegation that Samourai lied about how it received sidebar placement and free advertising.³¹

A sample of replies from the official Samourai Wallet account. The language is reproduced because the conduct itself is part of the record.

The volume and repetition make these exchanges more than a momentary failure of tone. Intimidation became part of the product’s public identity.

When you wrestle with a pig, you both get dirty

The screenshots document individual incidents but cannot convey their cumulative effect over several years.

I began to approach technical conversations as possible trials of character because bug reports, imprecise reporting, and edited audio could all be reframed as evidence of bad intent. Leaving a false claim unanswered allowed it to spread, while answering prolonged the conflict.

I spent time preserving evidence that I wanted to spend on code. Friends and independent developers had to decide whether correcting the record was worth becoming the next target. The authorship distortion affected me most: a framework I created was folded into a joint-origin myth, and the project that benefited from my premature credit presented me as an enemy of privacy.

I did not handle that well.

I called the project “Scamourai” and swore at them; in 2019, CoinDesk quoted one of my replies simply saying “Fuck you.”³² That anger produced little of value. The childish nickname allowed a long evidentiary record to be mistaken for reciprocal mudslinging and made it easier for outsiders to conclude that both sides were merely marketing tribes.

I also sometimes spoke with more certainty than the evidence allowed. Receiving an xpub, retaining it, selling it, and maliciously querying it are separate claims. I knew the default backend received wallet-level public information. Before the server analysis became public, I did not know everything Samourai retained or did with it. I should have marked those boundaries in an angry tweet as carefully as I would in a protocol review.

I regret the way I spoke. It made the documented issues easier to dismiss, even though it does not change the Git history or the evidence preserved here.

By April 2023, the conflict had passed far beyond professional hostility. I had received multiple death threats from William Hill—not one. I also received anonymous private threats during the same campaign. The screenshots alone cannot establish who controlled those anonymous accounts. After another dispute about Whirlpool’s Tor behavior, I wrote: “In case something happens to me... I just received a death threat from William Hill”. I did not publish every message, and what I did publish was only part of what I received.

My public statement on April 16, 2023, together with the reference I said I understood as threatening.

One private message sent me a full address in Besenyszög. I blacked out the street-level portion before supplying the screenshot below. Another sender claimed to have checked an address and seen me and my “stinking tribe,” asked whether I thought I could stay safe, and ended: “We shall meet. Won’t be pretty on your end.” An interface label is not enough to identify who controlled an anonymous account, so the screenshot establishes only what I received.

A private message containing a full address in Besenyszög. I supplied this image with the identifying portion already blacked out; the archive contains no uncensored copy.

A second anonymous account claimed to have checked an address and seen me, asked whether I thought I could stay safe, and threatened an eventual meeting. The screenshot records the message, not the sender’s identity.

The threats were accompanied by doxxing. Hill posted my parents’ home address more than once. I will not reproduce or link to those posts, because proving that it happened does not require exposing them again. His public @SamouraiDev profile still names me, says, “It ain’t over until the fat boy is gutted,” and appends the name of the small town where my parents live.¹⁷ Publishing my family’s location beside violent language was intimidation.

The public @SamouraiDev profile as preserved on July 10, 2026. I have not reproduced my parents’ street address.

The complete source image from the official Samourai Wallet account’s “Snitches get stitches” post, preserved again in my contemporaneous record on April 18, 2023. X’s timeline preview cuts off part of the text; this archived source image does not.

Two days later, Hill addressed me directly: “As a die hard collaborator, you deserve much worse.” He ended with, “Let’s see how this plays out, OK bud?” The attached image showed armed men surrounding a seated captive whose head was being shaved. I understood the combination of that image and those words as a threat.¹⁸

Hill’s April 20, 2023 post paired “you deserve much worse” with an image of an armed public punishment. Open the post.

The campaign continued the next year. In February 2024, Hill wrote that I was “way overdue to get yours” and appended #Besenyszög. A follower replied, “Hope he gets stitches and ends up in a ditch.” Hill answered: “Yes.” Then: “Soon.”¹⁸

The public February 20, 2024 thread: a location-linked warning, a reply hoping I would end up in a ditch, and Hill’s “Yes” and “Soon.” Open the first post and Hill’s reply.

Six weeks later, Hill made the violent reference unmistakable. “It ain’t over until the fat boy is gutted (see bio),” he wrote above Yasushi Nagao’s famous photograph of the assassination of Japanese Socialist Party chairman Inejirō Asanuma. I had incorrectly remembered the victim as a Japanese prime minister; the recovered post identifies him correctly. That correction does not change the nature of Hill’s post.¹⁸

Hill’s April 4, 2024 post paired “gutted” with the photograph of Asanuma’s onstage assassination. Open the post.

The criminal case later produced records independent of the feud.

What the server seizure revealed

When Samourai’s founders were arrested in April 2024, I refused to treat the indictment as a verdict. Privacy software is not money laundering merely because criminals use it. The legal boundary around noncustodial software was—and remains—important.

But law enforcement also seized Samourai’s servers, and the later filings addressed technical issues I had been raising for years.

In an October 2025 sentencing memorandum, the government said its analysis showed that Rodriguez and Hill had retained enough information to trace or “demix” mobile users’ Whirlpool transactions. By cross-referencing stored xpubs with past, present, and future Whirlpool transactions, an analyst could connect the inputs and outputs of many transactions through complex analysis. The filing also stated an important limit: this did not by itself connect those transactions to real-world identities.³³

The government’s description of the server analysis: retained mobile-user xpubs could be cross-referenced with Whirlpool transactions to connect inputs and outputs, without by itself identifying the real-world user. Open the archived filing.

The defense did not deny xpub collection. Hill’s sentencing submission tried to recast it as a functional necessity: users without their own nodes needed the backend to calculate their balances, it said, and the design affected “only 20%” of Whirlpool users. That was a consequence of Samourai’s chosen architecture, not a universal requirement of light wallets. Wasabi obtained block filters and checked addresses on the client without giving our server the wallet’s xpub.² The filing also gave no source, methodology, underlying counts, or independent measurement for its percentage. It may have been nothing more than a figure supplied by Samourai and repeated by its lawyers. The submission gives us no way to know.³³

“Only” is doing a great deal of work there. So is the unsourced percentage.

Even if the defense’s estimate is accepted for the sake of argument, one in five Whirlpool users is a significant part of the user base. More importantly, the argument concedes the architecture I had objected to: a class of users provided its wallet graph to Samourai’s infrastructure; Samourai retained that information; and the seizure placed it in government hands.

Dojo was not a practical escape for wallet users during Samourai’s first four years. Its server code was released on June 2, 2019, but Samourai’s announcement said the wallet still needed another update before it could pair with Dojo. Version 0.99.81 added pairing on July 11 and supported only newly created wallets; restoring an existing wallet was explicitly unsupported. An earlier user who wanted to stop using Samourai’s servers at that point had to create a new wallet behind Dojo and move the balance out of the old one. That prevented the new wallet’s xpub from being disclosed, but it could not erase the old xpub and history already sent to Samourai. A direct transfer between the wallets would also remain visible on-chain.⁴

The June 2025 superseding indictment reproduced private messages and Dread posts in which Hill steered people who openly described criminal proceeds away from a competing mixer and toward Whirlpool. It said Rodriguez knew Hill was conducting substantial promotional work on Dread.³⁴

Pages 10–11 of the superseding indictment reproduce the Dread context and allege that Hill steered users describing criminal proceeds toward Whirlpool, while Rodriguez knew he was doing promotional work there. An indictment is an allegation, not a verdict; both men later entered guilty pleas to the offense described below. Open the archived indictment.

This mattered because Samourai and OXT had repeatedly turned criminal use of Wasabi into part of the public case against us. Yet the later record showed Samourai pursuing those same users as customers. On Dread, competitor disparagement was not an abstract contribution to privacy research. It was a sales pitch aimed at people asking how to conceal criminal proceeds.

On July 30, 2025, Rodriguez and Hill each pleaded guilty to conspiring to operate a money-transmitting business knowing it transmitted crime proceeds. The money-laundering conspiracy count was dropped through the plea agreements. The Justice Department announced the pleas on August 6, and its account included their Dread marketing.³⁵ In November, Rodriguez received five years in prison and Hill four.³⁶

The sentences did not resolve the software issues, and the prosecution raised troubling questions of its own. Before the pleas, the defense argued that prosecutors had disclosed too late a FinCEN communication saying Samourai’s lack of control over users’ keys strongly suggested it was not a money-services business under FinCEN’s rules. The government disputed the communication’s significance.³⁷ Anyone who cares about open-source privacy software should care about that due-process issue.

The case added previously unavailable information about retention, intent, and marketing, although the sentences themselves say nothing about who was right technologically.

The lies and hypocrisies

Developers can be mistaken, remember events differently, or speak with unjustified confidence. I use “lie” more narrowly: a materially false account repeated after contrary evidence has been presented because the false version remains useful.

By that standard, the ZeroLink co-creation story was a lie. The framework predated Samourai’s involvement; the first Samourai contribution fixed typos; and they repeated the joint-origin account years after I challenged it with the repository.¹²⁵

The claim that I had admitted Wasabi supplied its own liquidity was false. The journalist corrected that interpretation, but Samourai continued promoting the damaging version while omitting my correction.

The categorical Tor answer was false. The public record cannot establish whether Rodriguez knowingly lied or answered with reckless certainty, but it does show that he insulted the questioner and that the code later added the identity change the question had asked about.²³

The “full node wallet” claim was false too. It appeared in a thread explicitly about the default app sending xpubs to Samourai, after the official account had defended its chosen backend architecture. A user-run Dojo could place the backend on the user’s full node. Without Dojo, the Android app was a light client of Samourai’s backend.³

Samourai’s use of OXT was another direct hypocrisy. It denounced surveillance companies while owning and operating a blockchain tracing and wallet-attribution tool of its own. It then used that tool’s research label to issue a severe public warning against its principal competitor. OXT’s own declared rule was that privacy must be protected by the software’s defaults, not by work pushed onto the user. Samourai’s default collected the xpubs; avoiding that collection required the user to run Dojo.⁸²

The coordinator-fee address shows the double standard directly. In February 2020, Samourai condemned Wasabi’s reuse of such an address in absolute terms. Even after Wasabi changed it, Samourai said the damage had already been done: “There’s no going back from more than a year of address reuse.” In October 2023, Kruw reported on Samourai’s own GitLab that Whirlpool’s coordinator had reused one fee address across 37 transactions. In one transaction cited in the report, 36 outputs from that address were consolidated as inputs.¹⁰

The reuse alone does not prove that Whirlpool users were demixed. The TX0 fee output was already recognizable, and a contemporary critic argued that rotating its address would not improve Whirlpool’s CoinJoin privacy. The issue is the standard Samourai applied: it described the same practice in Wasabi as irreversible architectural damage, while Kruw says his Whirlpool report was deleted. The surviving Wayback capture is an open issue archived less than a minute after it was filed, so the deletion claim rests on Kruw’s same-day account rather than a later Wayback capture.¹⁰

The privacy promise itself was contradicted by the product’s defaults. Samourai marketed resistance to financial surveillance while the wallet sent xpubs to its hosted backend and left Tor off unless the user enabled it. The hosted service could therefore receive the wallet graph and the connecting IP address together. They also called Sentinel the “easiest and most secure” way to watch cold storage, while its hosted-server mode handed Samourai the xpub that allowed Samourai to watch it too. When the wallet’s unsafe defaults were reported on Samourai’s GitLab, the project owner rejected the proposed change, threatened the reporter, and closed the issue. The server seizure later demonstrated why the backend’s wallet-level information mattered.^2151633

Samourai also used criminal association selectively. It repeatedly tried to turn alleged criminal use of Wasabi into a case against us while privately promoting Whirlpool to darknet users who openly described criminal proceeds.³⁴³⁵

zkSNACKs deserved criticism for blacklisting, but that policy did not turn Wasabi into a surveillance wallet. The coordinator decided which inputs to accept while the blinded design still prevented it from linking those inputs to their outputs. Samourai’s default backend, by contrast, retained wallet-level information.²²⁶³³

I use the name Scamourai to describe what I see as a false central promise, not as a legal accusation of fraud. The product sold protection from surveillance while placing its operator in a position to surveil, and it promoted verification while requiring default users to trust that Samourai would not misuse wallet information that its servers retained. To me, this went beyond imperfect privacy because the contradiction was built into the default architecture.

Post-mortem

The lasting damage was to the authorship record and to the possibility of productive competition. I gave TDevD more credit than the repository justified, and Samourai inflated that credit into co-creation. Minor edits became joint research through repetition. The same culture made correction look like surrender and uncertainty look like weakness, turning technical competition into personal hostility.

I contributed to that hostility by answering contempt with contempt. I cannot undo those words, but I can document the history more carefully now.

Future privacy developers should not take this essay as a request to trust me or as a rule that every server and coordinator is unacceptable. The practical lesson is to examine what an operator can learn if its infrastructure is compromised, coerced, or seized. Team identity and a founder’s character are not privacy guarantees. A sound protocol should continue protecting users when trust in the operator fails.

Sources and notes

Further reading

• BlockDigest, SHI256 episode 1, July 2019. Shinobi distinguishes the architectures and records the contemporary “two competing approaches” view; that framing does not negate the default xpub disclosure.
• Yuval Kogman, “Unbreaking Whirlpool’s Privacy”, Bitcoin Development Mailing List, December 2024. Kogman discloses his connection to WabiSabi and analyzes a coordinator key-consistency problem affecting both protocol families; he states that he found no evidence the Whirlpool coordinator had exploited it.
• WalletScrutiny, historical reproducibility record for Samourai Wallet. Results varied by release and build conditions; the current seizure-era status should not be projected backward onto every version.
• nopara73, ScamouraiWallet source archive. The archive preserves useful leads but contains mislabeled links; this essay relies on the underlying sources rather than treating the repository’s labels as evidence.