<p>Depending on your usecase...
If you just need to know it exists, then you can scan the chain (db-sync, chain-index, blockfrost,...)</p>
<p>If you need to verify it against a minting policy, you'll obvs need access to that too and do the hashing like what KtoZ says. There are however resources listing currency symbols. (TBC, but) CardanoScan records and verifies native scripts (not plutus atm)</p>

CC BY-SA 4.0
2022-04-16T10:34:12.400Z
2022-04-16T10:34:12.400Z
waalge
<p>Beyond the length of the hash digest (28 bytes in this case), no. Unless you have the pre-image (that is, the raw policy script) in which case you can rehash it and compare.</p>

CC BY-SA 4.0
2022-04-16T09:32:40.883Z
2022-04-16T09:32:40.883Z
KtorZ
<p>im trying to build something in cardano, and i want to check if policy id provided by the user is an actual policyid?
after research i found that blake2b_224 is used for hashing the policy id,is there away to validate that a string was blake2b_224 hashed</p>

<token><cardano-address><bech32><hash><blake2b>
Is there a way to validate a policy Id,and to check if a string is an actual policy id?
# Is there a way to validate a policy Id,and to check if a string is an actual policy id?

(Asked by: username_0 on 2022-04-15)

im trying to build something in cardano, and i want to check if policy id provided by the user is an actual policyid?
after research i found that blake2b\_224 is used for hashing the policy id,is there away to validate that a string was blake2b\_224 hashed

**Tags:** token, cardano-address, bech32, hash, blake2b

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## 2 answers

### Answer by username_1 on 2022-04-16. Score: 0 | Accepted answer

Depending on your usecase...
If you just need to know it exists, then you can scan the chain (db-sync, chain-index, blockfrost,...)

If you need to verify it against a minting policy, you'll obvs need access to that too and do the hashing like what KtoZ says. There are however resources listing currency symbols. (TBC, but) CardanoScan records and verifies native scripts (not plutus atm)


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### Answer by username_2 on 2022-04-16. Score: 1

Beyond the length of the hash digest (28 bytes in this case), no. Unless you have the pre-image (that is, the raw policy script) in which case you can rehash it and compare.


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