diff --git a/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption-metadata.mp4 b/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption-metadata.mp4
index 8fff861..9aa56a2 100644
Binary files a/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption-metadata.mp4 and b/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption-metadata.mp4 differ
diff --git a/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption.pdf b/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption.pdf
index 2a01af4..69273b6 100644
Binary files a/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption.pdf and b/src/teaching/2024_2025_-_Crypto_eng/crypto_eng_02_symmetric_encryption.pdf differ
diff --git a/src/teaching/2024_2025_-_Crypto_eng/index.org b/src/teaching/2024_2025_-_Crypto_eng/index.org
index 1b41064..43d25d5 100644
--- a/src/teaching/2024_2025_-_Crypto_eng/index.org
+++ b/src/teaching/2024_2025_-_Crypto_eng/index.org
@@ -9,5 +9,6 @@
 ** TD
 - TD 1: [[./crypto_eng_td_01.pdf][Proof methods and OT/PRF/PRG]]
 - TD 2: [[./crypto_eng_td_02.pdf][IND-CPA security]]
+- TD 3: [[./crypto_eng_td_02.pdf][Hash functions]]