i get the following errors while trying to update
Hit http://http.kali.org sana InRelease
Get:1 http://http.kali.org sana/main Sources [9,089 kB]
Get:2 http://security.kali.org sana/updates InRelease [17.1 kB]
1% [2 InRelease gpgv 17.1 kB] [1 Sources 69.8 kB/9,089 kB 1%] [Waiting for heaSplitting up /var/lib/apt/lists/partial/security.kali.org_kali-security_dists_saErr http://security.kali.org sana/updates InRelease

Ign http://http.kali.org sana/contrib Translation-en_US
Ign http://http.kali.org sana/contrib Translation-en
Ign http://http.kali.org sana/main Translation-en_US
Ign http://http.kali.org sana/main Translation-en
Ign http://http.kali.org sana/non-free Translation-en_US
Ign http://http.kali.org sana/non-free Translation-en
Get:3 http://http.kali.org sana/non-free Sources [123 kB]
Get:4 http://http.kali.org sana/contrib Sources [58.3 kB]
Get:5 http://http.kali.org sana/main amd64 Packages [12.8 MB]
Get:6 http://http.kali.org sana/non-free amd64 Packages [164 kB]
Get:7 http://http.kali.org sana/contrib amd64 Packages [87.7 kB]
Fetched 22.3 MB in 4min 16s (87.0 kB/s)
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://security.kali.org sana/updates InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)

W: Failed to fetch http://security.kali.org/kali-securi...ates/InRelease

W: Some index files failed to download. They have been ignored, or old ones used instead.





My sources.list
# deb cdrom:[Debian GNU/Linux 2.0 _Sana_ - Official Snapshot amd64 LIVE/INSTALL Binary 20150811-08:02]/ sana contrib main non-free

#deb cdrom:[Debian GNU/Linux 2.0 _Sana_ - Official Snapshot amd64 LIVE/INSTALL Binary 20150811-08:02]/ sana contrib main non-free
#Regular
deb http://http.kali.org/kali sana main non-free contrib
deb http://security.kali.org/kali-security sana/updates main contrib non-free

#Source
deb-src http://http.kali.org/kali sana main non-free contrib
deb-src http://security.kali.org/kali-security sana/updates main contrib non-free