Why does the participants send their private key?? Shouldn't they send their public key instead?
Also, I doubt it is possible to deal with a bitcoin user with only one address.
Making a bitcoin-pegged currency is a fair idea. But there are certainly much simpler ways to do so.
You might consider the loom project for instance. Or opentransaction, LETS and other complementary currencies software.
Also, please notice I wrote some bash functions that allow to turn a openssl generated public key into a bitcoin address:
#!/bin/bash
#
# This is free and unencumbered software released into the public domain.
#
# Requires bc, dc, openssl, xxd
#
base58=({1..9} {A..H} {J..N} {P..Z} {a..k} {m..z})
bitcoinregex="^[$(printf "%s" "${base58[@]}")]{34}$"
decodeBase58() {
local s=$1
for i in {0..57}
do s="${s//${base58[i]}/ $i}"
done
dc <<< "16o0d${s// /+58*}+f"
}
encodeBase58() {
# 58 = 0x3A
bc <<<"ibase=16; n=${1^^}; while(n>0) { n%3A ; n/=3A }" |
tac |
while read n
do echo -n ${base58[n]}
done
}
checksum() {
xxd -p -r <<<"$1" |
openssl dgst -sha256 -binary |
openssl dgst -sha256 -binary |
xxd -p -c 80 |
head -c 8
}
checkBitcoinAddress() {
if [[ "$1" =~ $bitcoinregex ]]
then
h=$(decodeBase58 "$1")
checksum "00${h::${#h}-8}" |
grep -qi "^${h: -8}$"
else return 2
fi
}
hash160() {
openssl dgst -sha256 -binary |
openssl dgst -rmd160 -binary |
xxd -p -c 80
}
hash160ToAddress() {
printf "%34s\n" "$(encodeBase58 "00$1$(checksum "00$1")")" |
sed "y/ /1/"
}
publicKeyToAddress() {
hash160ToAddress $(
openssl ec -pubin -pubout -outform DER |
tail -c 65 |
hash160
)
}
So if you want to create a private key and see the corresponding bitcoin address, you can run:
$ openssl ecparam -name secp256k1 -genkey |tee priv.pem| openssl ec -pubout |publicKeyToAddress
