Bitcoins address is what you all already know.
Now, whats compressed bitcoin address?
Its just a compressed way of storing your key in fewer bytes (33 in Place of 65). They won't cause any problems or security issues as they are the same keys stored in just a different way. They have no disadvantages other than that a little bit of additional computation is needed before they can be used to validate a signature.
Topic: What is Compressed Address ? (Read 833 times)
Most wallets should use compressed addresses now. They reduce the size of the transaction. If you import a WIF encoded private key starting with 5 the wallet will assume an uncompressed pubkey. If you use a WIF encoded private key starting with L or K the wallet will assume a compressed pubkey. Its probably an issue with the brainwallet software you used. It should display two WIF encoded private keys. The private key is still the same, its just a different prefix.
one priv key (hex format) --> two private keys (WIF format) --> two pubkeys (compressed / uncompressed) -> two addresses
I don't use any software to generate the brainwallet, I've used bitaddress.org to generate it.one priv key (hex format) --> two private keys (WIF format) --> two pubkeys (compressed / uncompressed) -> two addresses
BTW I have just tried with my private key exported from blockchain.info for my address 17sy7mX9t8CsnYM39bs4pQ3aVtgeanyu63. The corresponding 'compressed' address is 15VS1AbU4GBY95SrDF9hBbmoQysQzkVvX7, however I haven't seen that address in any software. When I imported it into Mycelium, the address shown is also the original one.
P.S. I've used the key to sign a message, and use the compressed address to verify it, however the original address shown: http://coinig.com/?adr=15VS1AbU4GBY95SrDF9hBbmoQysQzkVvX7&msg=Test+message.+Today+is+16-11-2015.&sig=HE%2BbQuXm44iiDIshC4FbRBkj9ZTUJd%2Bh%2Br%2Boh5ib9xP0UAmdGAtxWQCZ9eaM47WYhwAVNNqr3bH%2BwF38TMSZJIU%3D
Edit: Right before I made this post, I've made a try on the compressed private key (start with a 'L') and the 'compressed' address shown.
Thats a good idea to reduce size of transaction.
Just google it for you!
You're not answering what exactly he was asking, he is asking compressed ADDRESS, like for the private key 5KgKbZCRc8VvwHcx76hvUdo1oDjh6pYMgbDgkvgeNi2r4gYy4HA (from brain wallet 123456789012345678901234567890), it's corresponding address is 1ECWivMucRHnFuRzSsSDWUWwnUQvxX9t2T while the corresponding COMPRESSED address is 13EgNfFRBpigdhwiXYnfVNS5seRfBJKyU5.Quote
A compressed key is just a way of storing a public key in fewer bytes (33 instead of 65). There are no compatibility or security issues because they are precisely the same keys, just stored in a different way. The original Bitcoin software didn't use compressed keys only because their use was poorly documented in OpenSSL. They have no disadvantages other than that a little bit of additional computation is needed before they can be used to validate a signature.
If you think of a public key as a point somewhere along a giant letter U, an uncompressed key is the x and y coordinates of the point. A compressed key is how high up on the U the point is along with a single bit indicating whether it's on the left or right side. As you can visualize, they both encode precisely the same thing, but the compressed form requires half as much space plus one bit. (Of course, they're really points on elliptic curve secp256k1, but the concept is the same.)
from http://bitcoin.stackexchange.com/questions/3059/what-is-a-compressed-bitcoin-key.If you think of a public key as a point somewhere along a giant letter U, an uncompressed key is the x and y coordinates of the point. A compressed key is how high up on the U the point is along with a single bit indicating whether it's on the left or right side. As you can visualize, they both encode precisely the same thing, but the compressed form requires half as much space plus one bit. (Of course, they're really points on elliptic curve secp256k1, but the concept is the same.)
I don't quite know how it works, however I would never send any bitcoins to a compressed address as many software don't recognize it (like I have just tested it in Mycelium, and it showed the normal address only).
Most wallets should use compressed addresses now. They reduce the size of the transaction. If you import a WIF encoded private key starting with 5 the wallet will assume an uncompressed pubkey. If you use a WIF encoded private key starting with L or K the wallet will assume a compressed pubkey. Its probably an issue with the brainwallet software you used. It should display two WIF encoded private keys. The private key is still the same, its just a different prefix.
one priv key (hex format) --> two private keys (WIF format) --> two pubkeys (compressed / uncompressed) -> two addresses
Just google it for you!
You're not answering what exactly he was asking, he is asking compressed ADDRESS, like for the private key 5KgKbZCRc8VvwHcx76hvUdo1oDjh6pYMgbDgkvgeNi2r4gYy4HA (from brain wallet 123456789012345678901234567890), it's corresponding address is 1ECWivMucRHnFuRzSsSDWUWwnUQvxX9t2T while the corresponding COMPRESSED address is 13EgNfFRBpigdhwiXYnfVNS5seRfBJKyU5.Quote
A compressed key is just a way of storing a public key in fewer bytes (33 instead of 65). There are no compatibility or security issues because they are precisely the same keys, just stored in a different way. The original Bitcoin software didn't use compressed keys only because their use was poorly documented in OpenSSL. They have no disadvantages other than that a little bit of additional computation is needed before they can be used to validate a signature.
If you think of a public key as a point somewhere along a giant letter U, an uncompressed key is the x and y coordinates of the point. A compressed key is how high up on the U the point is along with a single bit indicating whether it's on the left or right side. As you can visualize, they both encode precisely the same thing, but the compressed form requires half as much space plus one bit. (Of course, they're really points on elliptic curve secp256k1, but the concept is the same.)
from http://bitcoin.stackexchange.com/questions/3059/what-is-a-compressed-bitcoin-key.If you think of a public key as a point somewhere along a giant letter U, an uncompressed key is the x and y coordinates of the point. A compressed key is how high up on the U the point is along with a single bit indicating whether it's on the left or right side. As you can visualize, they both encode precisely the same thing, but the compressed form requires half as much space plus one bit. (Of course, they're really points on elliptic curve secp256k1, but the concept is the same.)
I don't quite know how it works, however I would never send any bitcoins to a compressed address as many software don't recognize it (like I have just tested it in Mycelium, and it showed the normal address only).
Just google it for you!
Quote
A compressed key is just a way of storing a public key in fewer bytes (33 instead of 65). There are no compatibility or security issues because they are precisely the same keys, just stored in a different way. The original Bitcoin software didn't use compressed keys only because their use was poorly documented in OpenSSL. They have no disadvantages other than that a little bit of additional computation is needed before they can be used to validate a signature.
If you think of a public key as a point somewhere along a giant letter U, an uncompressed key is the x and y coordinates of the point. A compressed key is how high up on the U the point is along with a single bit indicating whether it's on the left or right side. As you can visualize, they both encode precisely the same thing, but the compressed form requires half as much space plus one bit. (Of course, they're really points on elliptic curve secp256k1, but the concept is the same.)
from http://bitcoin.stackexchange.com/questions/3059/what-is-a-compressed-bitcoin-key. If you think of a public key as a point somewhere along a giant letter U, an uncompressed key is the x and y coordinates of the point. A compressed key is how high up on the U the point is along with a single bit indicating whether it's on the left or right side. As you can visualize, they both encode precisely the same thing, but the compressed form requires half as much space plus one bit. (Of course, they're really points on elliptic curve secp256k1, but the concept is the same.)
What is a Compressed Address ? what is different between a ordinary Address and Compressed Address ? why have they different Privkeys ?
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