diff --git a/TODO b/TODO
index 90e8be2..da101e3 100644
--- a/TODO
+++ b/TODO
@@ -11,3 +11,4 @@ resources:
 	https://crypto.stackexchange.com/questions/3608/why-is-padding-used-for-rsa-encryption-given-that-it-is-not-a-block-cipher
 	https://www.inf.pucrs.br/~calazans/graduate/TPVLSI_I/RSA-oaep_spec.pdf
 	https://stackoverflow.com/questions/17298130/working-with-large-primes-in-python
+	RSA Primitives documentation PKCS: https://tools.ietf.org/html/rfc8017#section-4