Common misconceptions
Things people often assume about Umbra that are not true, each corrected with what the protocol actually does.
Each item below is something a reasonable reader might assume, followed by what the code does.
"Deposits are private."
They are not. A deposit shows the depositing wallet, the token and the amount, and the depositing wallet is publicly tied to your identity. What is private is what happens to the value afterwards.
"Nobody can link my deposit to my withdrawal."
The chain records no link between them. Amounts and timing can still suggest one, if a withdrawal looks like the deposit before it. See privacy practices.
"Umbra itself cannot see anything."
The indexer's context service sees which notes you spend. The fee enclave sees fee totals. See what is private and what is visible.
"The guardians could take my funds."
They cannot. A spend needs a zero-knowledge proof made with keys only your account has. The guardians co-sign transactions and hold viewing-key shares; neither lets them spend. What they can do is refuse to sign, which stops transactions until you use the escape hatch. See what guardian nodes can and cannot do.
"A relayer could redirect my payment."
It cannot. Every account but its own and every field of the payload are bound into the digest that the attesters sign and the proof commits to. A relayer can only submit the transaction as it is or refuse to. See relayers.
"The escape hatch is a private exit."
It is the opposite. It works without any attester, and in exchange it discloses the note's fields, including its owner, on chain. See the escape hatch.
"A quantum computer could read my notes later."
Notes are encrypted with ML-KEM-768, a post-quantum key encapsulation, so recorded notes stay private against that threat. The proofs and signatures are not post-quantum: a future quantum attacker could forge them from then on, but forging does not reveal past notes. See security levels.
"If one service goes down, the others carry on."
Every value transaction needs all six attesters to sign. If any one is down, value transactions stop until it returns, and the escape hatch is the way out meanwhile. See liveness.
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Metadata and network privacy
What leaves your device besides the transaction itself, who receives it, and what the protocol can and cannot do about it.
Trust assumptions
What you rely on for your funds to be safe, your activity to stay private and the protocol to keep running, who holds which power, and what no one can do.