diff --git a/src/condensed.py b/src/condensed.py
new file mode 100644
--- /dev/null
+++ b/src/condensed.py
@@ -0,0 +1,111 @@
+# GNU GPLv3, see LICENSE
+# easier to print, single file, reconstruct-only version of the code
+# encoding fixed to Base32
+# Python 3.6
+# full version available at https://bitbucket.org/Scharlach/shamira
+
+"""Arithmetic operations on Galois Field 2**8. See https://en.wikipedia.org/wiki/Finite_field_arithmetic"""
+
+
+def gfmul(a,b):
+	"""Basic multiplication. Russian peasant algorithm."""
+	res=0
+	while a and b:
+		if b&1: res^=a
+		if a&0x80: a=0xff&(a<<1)^0x1b
+		else: a<<=1
+		b>>=1
+	return res
+
+
+g=3 # generator
+E=[None]*256 # exponentials
+L=[None]*256 # logarithms
+acc=1
+for i in range(256):
+	E[i]=acc
+	L[acc]=i
+	acc=gfmul(acc, g)
+L[1]=0
+inv=[E[255-L[i]] if i!=0 else None for i in range(256)] # multiplicative inverse
+
+
+def getConstantCoef(*points):
+	"""Compute constant polynomial coefficient given the points.
+
+	See https://en.wikipedia.org/wiki/Shamir's_Secret_Sharing#Computationally_Efficient_Approach"""
+	k=len(points)
+	res=0
+	for i in range(k):
+		(x,y)=points[i]
+		prod=1
+		for j in range(k):
+			if i==j: continue
+			(xj,yj)=points[j]
+			prod=gfmul(prod, (gfmul(xj,inv[xj^x])))
+		res^=gfmul(y,prod)
+	return res
+
+###
+
+import base64
+import binascii
+
+
+def reconstructRaw(*shares):
+	"""Tries to recover the secret from its shares.
+
+	:param shares: ((i, (bytes) share), ...)
+	:return: (bytes) reconstructed secret. Too few shares returns garbage."""
+	secretLen=len(shares[0][1])
+	res=[None]*secretLen
+	for i in range(secretLen):
+		points=[(x,s[i]) for (x,s) in shares]
+		res[i]=(getConstantCoef(*points))
+	return bytes(res)
+
+
+def reconstruct(*shares):
+	"""Wraps reconstructRaw.
+
+	:param shares: ((str) share, ...)
+	:return: (str) reconstructed secret. Too few shares returns garbage."""
+
+	bs=reconstructRaw(*(decode(s) for s in shares))
+	return bs.decode(encoding="utf-8")
+
+
+
+def decode(share):
+	try:
+		(i,_,shareStr)=share.partition(".")
+		i=int(i)
+		if not 1<=i<=255:
+			raise ValueError()
+
+		shareBytes=base64.b32decode(shareStr)
+		return (i,shareBytes)
+	except (ValueError,binascii.Error):
+		raise ValueError('bad share format: share="{0}"'.format(share))
+
+###
+
+from argparse import ArgumentParser
+
+
+def run():
+	parser=ArgumentParser()
+	subparsers=parser.add_subparsers()
+
+	joiner=subparsers.add_parser("join")
+	joiner.add_argument("share",nargs="+",help="shares to be joined")
+	joiner.set_defaults(func=lambda args: print(reconstruct(*args.share)))
+
+	parser.set_defaults(func=lambda: parser.error("missing command"))
+
+	args=parser.parse_args()
+	args.func(args)
+
+
+if __name__=="__main__":
+	run()