Block's Dessa voice AI sounds almost human. Here's how to protect your crypto from voice-clone scams

Block, the company behind Cash App and the Bitkey bitcoin wallet, has shown off a voice AI called Dessa that sounds strikingly like a real person. The demos impressed many listeners and worried others, who see a new tool for phone scams. Here is what Block actually released, what it hasn't, and how to keep your crypto safe from voice-clone scams either way.

What Block showed

Block says Dessa is a "full-duplex" speech model: like a person on the phone, it can hear you while it is still speaking, which means it can be interrupted, jump in and make small "yeah" and "got it" sounds. Block's main claims:

• Trained on sound only. Block says it built Dessa from scratch on human conversation, with no text and no pretrained models. Block says most current voice AI turns your speech into text first, then answers.
• Live, unscripted demos. According to Block, every clip on its page was recorded live as someone chatted with the model, and nobody steers its answers. In one, it laughs mid-sentence; in another, it gasps at a surprise.
• Small hardware. Block says it trained Dessa on a single Nvidia GB200 NVL72 system and that it can run on a laptop: an M4 Max MacBook Pro or anything more powerful.

Block's page says talking with Dessa "feels like talking with a person." Keep in mind these are company demonstrations, not independent tests.

What it isn't (yet)

• Not a public product. Block is letting a handful of outside AI safety researchers test it first, to find risks its team may have missed. Everyone else can join a waitlist.
• Not fully disclosed. As CoinDesk noted, Block hasn't said how big the model is, shared benchmark scores, or set a date for a public release.
• Not a crypto product. Dessa comes from a small AI research lab inside Block that reports to Dorsey. Block hasn't said Dessa will be built into Cash App or Bitkey.

Why people worry about scams

CoinDesk reported that reactions split between amazement and alarm. Filmmaker Justine Bateman asked why AI voices need to sound human at all, and journalist Shiv Aroor wrote that scam calls were "about to attain pandemic level." Block's own pitch is about safety in the other direction: it argues that an AI which can hear emotion could notice when a person is in distress.

The worry isn't new. The FBI's 2025 internet crime report, released in April 2026, was the first to include a section on artificial intelligence, and the FBI listed voice clones among the tools scammers use. In a December 2024 public service announcement, the FBI warned that criminals use AI-generated audio to pose as a loved one in a crisis and ask for urgent money or a ransom, and to break into bank accounts by impersonating the account holder. Its list of things never to send to people you have only met online or by phone includes cryptocurrency. The FTC has warned about the same trick: a cloned voice of a family member who calls in trouble and asks you to send money right away.

Scammers like being paid in crypto for a reason. The FTC notes that crypto payments "typically are not reversible": once you've paid, the money usually comes back only if the person you paid chooses to return it. There's no bank to call and no chargeback.

How to protect yourself

None of this depends on which AI the caller uses. The same habits beat a perfect fake and a clumsy one:

• Hang up and call back. If a "relative", your exchange or "support" calls with an emergency, end the call and ring them back on a number you already know is theirs. The FTC also suggests trying another family member or a friend if you can't reach the person.
• Agree on a family code word. The FBI suggests a secret word or phrase that your family uses to confirm who's really calling. Pick one that isn't on social media.
• Never send crypto because of a phone call. The FTC says no legitimate business or government will "demand that you buy or pay with cryptocurrency." Pressure to act right now is the warning sign.
• Never read out your seed phrase or a login code. No legitimate exchange or wallet company will ask for it, by voice or any other way. See our guide to impersonation scams.
• Share less of your voice in public. The FBI suggests limiting online content of your image or voice and keeping social accounts private where you can.

Not sure about a message, link or request? Run it through our free Scam Check before you act.

If it already happened

File a report with the FBI at ic3.gov (its Internet Crime Complaint Center) and with the FTC at ReportFraud.ftc.gov. Include the phone number, the wallet addresses and the transaction details. Then watch for recovery scams: people who promise to get your crypto back for a fee are very often the next scam.

The takeaway

Block's Dessa shows how human AI voices are starting to sound, even though it isn't public yet. The safest assumption is that any voice on the phone could be fake, and the fix is simple: verify on a number you know, use a code word, and never move crypto because a caller told you to. This is education, not financial advice, and it reflects Block's published information and FBI and FTC guidance as of October 25, 2026.

Published October 25, 2026 by Dave McNaught. Educational content, not financial, legal or tax advice. Spot an error? Request a correction.

About the author

Dave McNaught

Dave McNaught has worked in IT since 1999 and founded All Business Technologies (ABT) in 2003, a Boston-area firm providing Managed IT, Cybersecurity, Managed AI, Web Design and App Development. He publishes The Crypto Guide.

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