Is it possible to generate private and public keys using only a calculator? If not how many lines of code would it take to write a wallet generator, and how difficult would it be? How would you do this?


Bitcoin Address Generator in Obfuscated Python is a fun piece of Python 2.7 code:

_                   =r"""A(W/2,*M(3*G
       ashlib&as&h,os,re,bi    nascii&as&k;J$:int(
     k.b2a_hex(W),16);C$:C    (W/    58)+[W%58]if(W@
    [];X=h.new("rip           em    d160");Y$:h.sha25
   6(W).digest();I$                 d=32:I(W/256,d-1)+
  chr(W%256)if(d>0@"";                  U$:J(k.a2b_base
 64(W));f=J(os.urando       m(64))        %(H-U("AUVRIxl
Qt1/EQC2hcy/JvsA="))+      1;M$Q,R,G       :((W*W-Q-G)%P,
(W*(G+2*Q-W*W)-R)%P)       ;P=H-2**       32-977;V$Q=P,L=
1,O=0:V(Q%W,W,O-Q/W*                      L,L)if(W@O%P;S,
T=A(f,U("eb5mfvncu6                    xVoGKVzocLBwKb/Nst
zijZWfKBWxb4F5g="),      U("SDra         dyajxGVdpPv8DhEI
qP0XtEimhVQZnEfQj/       sQ1Lg="),        0,0);F$:"1"+F(W
 [1:])if(W[:1           ]=="\0"@""        .join(map(B,C(
  J(W))));K$:               F(W          +Y(Y(W))[:4]);
   X.update(Y("\4"+                     I(S)+I(T)));B$
    :re.sub("[0OIl    _]|            [^\\w]","","".jo
     in(map(chr,ra    nge    (123))))[W];print"Addre
       ss:",K("\0"+X.dig    est())+"\nPrivkey:",K(
         "\x80"+I(f))""";exec(reduce(lambda W,X:
            W.replace(*X),zip(" \n&$@",["","",
               " ","=lambda W,",")else "])

I'd check out these two Python modules:

  1. Bitcoinaddress
  2. Pybitcointools (a fantastic Bitcoin library: see the README.txt for usage)

A private key is just/can be a very large number. However it's not possible to use a calculator to calculate an address easily, mainly because:

  • modular arithmetic is involved
  • base 58 check is not a straightforward conversion
  • there's appended bytes and such

I'd recommend either this web app to get the next best thing.

  • 1
    You also need a very good source of entropy, which a calculator (nor a human) possess. Absolutely never should you be outsourcing key generation to a third party as they (and everybody else watching your connection) can easily steal your money any time in the future.
    – Claris
    Apr 6 '15 at 1:59
  • 1
    @Bitcoin Very good point. The only feasible way of getting entropy without a library is by rolling dice. Apr 6 '15 at 2:04

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