aboutsummaryrefslogtreecommitdiff
path: root/src/crypto/crypto_ops_builder/ref10CommentedCombined/sqrtm1.py
diff options
context:
space:
mode:
authorRiccardo Spagni <ric@spagni.net>2015-08-24 19:34:10 +0200
committerRiccardo Spagni <ric@spagni.net>2015-10-26 18:00:53 +0200
commitbb0c161e7d4bff0e70b59c2f4267da96f34742af (patch)
tree6218bba2ad3cdaa4a8c0be027587db736a2cc946 /src/crypto/crypto_ops_builder/ref10CommentedCombined/sqrtm1.py
parentMerge pull request #448 (diff)
downloadmonero-bb0c161e7d4bff0e70b59c2f4267da96f34742af.tar.xz
renamed folder
Diffstat (limited to 'src/crypto/crypto_ops_builder/ref10CommentedCombined/sqrtm1.py')
-rw-r--r--src/crypto/crypto_ops_builder/ref10CommentedCombined/sqrtm1.py28
1 files changed, 28 insertions, 0 deletions
diff --git a/src/crypto/crypto_ops_builder/ref10CommentedCombined/sqrtm1.py b/src/crypto/crypto_ops_builder/ref10CommentedCombined/sqrtm1.py
new file mode 100644
index 000000000..9a47fbc12
--- /dev/null
+++ b/src/crypto/crypto_ops_builder/ref10CommentedCombined/sqrtm1.py
@@ -0,0 +1,28 @@
+q = 2**255 - 19
+
+def expmod(b,e,m):
+ if e == 0: return 1
+ t = expmod(b,e/2,m)**2 % m
+ if e & 1: t = (t*b) % m
+ return t
+
+def inv(x):
+ return expmod(x,q-2,q)
+
+def radix255(x):
+ x = x % q
+ if x + x > q: x -= q
+ x = [x,0,0,0,0,0,0,0,0,0]
+ bits = [26,25,26,25,26,25,26,25,26,25]
+ for i in range(9):
+ carry = (x[i] + 2**(bits[i]-1)) / 2**bits[i]
+ x[i] -= carry * 2**bits[i]
+ x[i + 1] += carry
+ result = ""
+ for i in range(9):
+ result = result+str(x[i])+","
+ result = result+str(x[9])
+ return result
+
+I = expmod(2,(q-1)/4,q)
+print radix255(I)