<p>My guess is that Satoshi did not know about the internals of ECDSA signatures, and simply used what OpenSSL gave him.</p>

<p>If it didn't require a hard forking change (requiring every wallet and verifying node on the network to upgrade), we'd have changed it long ago.</p>

CC BY-SA 3.0
2013-11-07T16:04:31.313Z
2013-11-07T16:04:31.313Z
Pieter Wuille
<p>A signature in secp256k1 is two 32 byte numbers. DER encoding a signature adds about 6-7 bytes.  It also needlessly complicates things (is DER encoding used anywhere else?).  In a transaction format that seems to try to squeeze every byte out, this is very strange to me.  Why not just use a 64 byte string to represent sigs instead? </p>

<signature><ecdsa>
Why use DER encoding for signatures?
user3243135
# Why use DER encoding for signatures?

(Asked by: username_0 on 2013-11-07)

A signature in secp256k1 is two 32 byte numbers. DER encoding a signature adds about 6-7 bytes. It also needlessly complicates things (is DER encoding used anywhere else?). In a transaction format that seems to try to squeeze every byte out, this is very strange to me. Why not just use a 64 byte string to represent sigs instead?

**Tags:** signature, ecdsa


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## 1 answers

### Answer by username_1 on 2013-11-07. Score: 16 | Accepted answer

My guess is that Satoshi did not know about the internals of ECDSA signatures, and simply used what OpenSSL gave him.

If it didn't require a hard forking change (requiring every wallet and verifying node on the network to upgrade), we'd have changed it long ago.


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