All posts by admin

Link collection homomorphic encryption algorithm

… is a form of encryption that allows computations to be carried out on ciphertext, thus generating an encrypted result which, when decrypted, matches the result of operations performed on the plaintext…

First publication: acm.org
Introduction: technologyreview.com
Details: en.wikipedia.org
Use in genomics: nature.com
R package: www.louisaslett.com

install.packages(c("Rcpp", "RcppParallel", "gmp")) 
install.packages("http://www.louisaslett.com/HomomorphicEncryption/dl/HomomorphicEncryption_0.2.tgz", repos=NULL)
library("HomomorphicEncryption")
p <- pars("FandV")
k <- keygen(p)
c1 <- enc(k$pk, c(42,34))
c2 <- enc(k$pk, c(7,5))
cres1 <- c1 + c2
cres2 <- c1 * c2
cres3 <- c1 %*% c2
dec(k$sk, cres1)
dec(k$sk, cres2)
dec(k$sk, cres3)

 

CC-BY-NC Science Surf accessed 19.01.2026

Ach je, Herr Urban

500 Jahre nach Martin Luthers Reformation hat sich die evangelische Kirche davon verabschiedet, auch Kirche der Aufklärung zu sein. Sie ist zum bloßen Sozialverein geworden, gefangen in einem archaischen Weltbild. Das Sagen haben zunehmend die antiintellektuellen, bildungsfeindlichen Fundamentalisten. Diese nehmen die Bibel wörtlich und missachten die Erkenntnisse der Wissenschaften einschließlich der Theologie. Ein fundamentalistischer Glaube provoziert heute weltweit in allen Religionen Intoleranz und Gewalt.
Martin Urban, Ach Gott, die Kirche! Protestantischer Fundamentalismus und 500 Jahre Reformation, dtv premium, 270 S., 14,90 €.

Urban, ehemaliger Wissenschaftsredakteur der süddeutschen Zeitung, arbeitet in seinem neuen Buch “Ach Gott, die Kirche” die Ressentiments gegen sein evangelisches Elternhaus ab. Seine Hauptthese: Im evangelischen Kirchenleben kommen Ergebnisse von historisch-kritischer Theologie nicht vor, wissenschaftliche Erkenntnisse spielen nur noch eine nachrangige Rolle, die Kirche wehrt sich nicht ausreichend gegen ihren politisch rechten, fundamentalistischen Flügel.

Auch wenn man die Kritik an den Konservativen teilen kann, so ist die Argumentation doch völlig verunglückt.  Fundamentalisten sind nahezu immun gegen externe  Kritik,  allenfalls durch systemimmanente subversive Rückfragen zu erreichen, wie es  Hubert Schleicher in einem wunderbaren Buch vorführt. Und allen anderen evangelischen Christen? Zumindest den kirchenfernen Mitgliedern wirft Urban damit das Austrittsformular in den Briefkasten. Continue reading Ach je, Herr Urban

 

CC-BY-NC Science Surf accessed 19.01.2026

No, there are no super humans

A new study – repeated by many newspapers – claims genes that rescue even in severe Mendelian disorder: cystic fibrosis, Smith-Lemli-Opitz syndrome, familial dysautonomia, epidermolysis bullosa simplex, Pfeiffer syndrome, autoimmune polyendocrinopathy syndrome, acampomelic campomelic dysplasia and atelosteogenesis.

A comprehensive screen of 874 genes in 589,306 genomes led to the identification of 13 adults harboring mutations for 8 severe Mendelian conditions, with no reported clinical manifestation of the indicated disease.

But we know about the reliability of 23andme results

Finally! 23 and the FDA warning

who even mixed up samples in the past.

Searching for genes that makes your resilient to disease is interesting of course but not very new with more examples of cystic fibrosis survivors available. Any new proof by the 23andme study is missing so far as the authors were unable to recontact any of the 13 resilient indiviuduals for whatever reasons.

 

CC-BY-NC Science Surf accessed 19.01.2026

Why allergy and vitamin D trials failed so far

The following figure highlights the exposure scheme in the three published vitamin D / allergy clinical trials so far: Grant 2016, Litonjua 2016 and Chawes 2016.

sc

None of them found anything important, maybe due to the design flaw in all these studies?

All three studies have been designed with the assumption of a beneficial vitamin D effect.

They are dose finding studies that do not allow to prove or disprove any vitamin D effect.

 

CC-BY-NC Science Surf accessed 19.01.2026

Up- and download in a single page application

This still not a trivial task given the patchwork of code pieces floating around. When writing a route finder app I came up with the following solution

# html
<form id="myform" enctype="multipart/form-data" action="upload.php" method="POST" target="_parent">
  <input type="hidden" name="uuid" value="1"/>
  <input id="myfile" type="file" name="file"  style="display: none;"/>
  <input type="submit" value="send" style="display: none;"/>
</form>

# query javascript that starts the upload
$("input[id='myfile']").click();

# upload.php
# note the redirect with javascript not with php allows to pass state parameters
$uuid=htmlspecialchars($_POST["uuid"]);
$uf = basename($_FILES['file']['name']);
$fn='data/'.$uuid.'.gpx';
if (move_uploaded_file($_FILES['file']['tmp_name'], $uf)) {
  rename($_FILES['file']['name'],$fn );
  file_put_contents ($fn , $txt, FILE_APPEND );
  echo '<script type="text/javascript">window.parent.location = "index.php";</script>';
}

The upload needs a quick refresh of the webpage (which could be avoided by posting to an hidden iframe and controlling response by an ajax call). The download doesn’t need a refresh:

# note the combined get and post commands
# don't know why this is necessary
$.ajax({
  data: "uuid="+fn,
  type: "post",
  url: "download.php",
  success: function() {
    window.location = 'download.php?uuid='+fn;
  }
});

 

CC-BY-NC Science Surf accessed 19.01.2026

Debunking myths

It is a big question in science how to identify and debunk myths. John Cook and Stephan Lewandowsky gives a free download of their debunking handbook

Debunking myths is problematic. Unless great care is taken, any effort to debunk misinformation can inadvertently reinforce the very myths one seeks to correct. To avoid these “back re effects”, an effective debunking requires three major elements. First, the refutation must focus on core facts rather than the myth to avoid the misinformation becoming more familiar. Second, any mention of a myth should be preceded by explicit warnings to notify the reader that the upcoming information is false. Finally, the refutation should include an alternative explanation that accounts for important qualities in the original misinformation.

 

CC-BY-NC Science Surf accessed 19.01.2026

Nicht in Gottes Namen

Zwei Buchempfehlungen:

Arnold Angenendt.Toleranz und Gewalt. Das Christentum zwischen Bibel und Schwert. Aschendorff Verlag, Münster 2006. ISBN 9783402002155. Gebunden, 797 Seiten, 24,80 EUR
Jonathan Sacks. Not in God’s Name: Confronting Religious Violence. Hodder adn Stoughton 2015. ISBN 9781473616523. Hardback 19,95 EUR

 

CC-BY-NC Science Surf accessed 19.01.2026

Track down the “no object… error in post.php”

Recently I encountered this strange error message in WordPress when trying to write a new post. Maybe I haven’t done any major changes, only removed a security plugin recently while the whole system is continuously updated.

Disabling all plugins and reverting to the standard twentyfifteen theme did not help. Inspection of post.php also did not show anything unusual (the indicated line number was probably wrong due to several includes). Googling the error message also did not help as these lead only to site specific problems. Continue reading Track down the “no object… error in post.php”

 

CC-BY-NC Science Surf accessed 19.01.2026

Blockchain – The next science revolution

There is a huge economical interest in bitcoins. And reading a bit more about the blockchain technology behind, I expect that scientific data will soon move towards the same path as soon as we drop Nature, Science and many more journals as gatekeepers

A block chain or blockchain is a permissionless distributed database based on a protocol that maintains a continuously growing list of data records hardened against tampering and revision, even by its operators. The initial and most widely known application of block chain technology is the public ledger of transactions for bitcoin,which has been the inspiration for similar implementations often known as altchains.

Although people are talking so much about releasing study data into the public domain – allowing reviewers to test central claims of a paper – there is no progress at all. Even being part of an EU funded collaborative study, I could never get the full data set.

Maybe it isn’t block chain alone – it may be also  cooperative storage cloud as in the following video example.

 

Added 31 Dec 2016: Blockchain started back in Jan 2009, occupies currently 105 GB and is distributed among 5400 nodes. Zündfunk (in German) has a nice feature about the blockchain referring mainly to the “Blockchain Revolution“, a new book by Don and Alex Tapscott.

 

CC-BY-NC Science Surf accessed 19.01.2026

WordPress Integrity: A simple intrusion detection

As I see so many scripts trying out wordpress vulnerabilities, it is just a matter of time until one bot will succeed. The only chance I see is to remove those unused themes and plugins, autoupdate wordpress and run weekly backups.

Another option is to monitor file integrity with this short php script

$cmd='find ./wordpress -type f -exec md5sum {} \;> ./hidden/wordpress.md5';
exec($cmd,$ret);
echo "<pre>"; print_r($ret); echo "</pre>";

Results can be seen with

$cmd='md5sum -c ./hidden/wordpress.md5 | grep -oh ".*FAILED.*"';

 

CC-BY-NC Science Surf accessed 19.01.2026