gluplot – a glucose level plot app with annotations

I had a Freestyle Libre sensor, a CGM (Continuous Glucose Monitoring) useful for diabetic or pre-diabetic patients, which allows you to measure your glucose...

C++ Implementation of Elliptic Curve

In my previous post, I implemented basic finite field and elliptic curve math and confirmed the public key generated in my code matches with...

WordPress glitches

Recently, I had trouble with updating on this site – WordPress doesn’t allow me to update any changes. Pressing “Update” button takes just long...

Understanding Elliptic Curve Cryptography

It’s getting tough but you can not avoid this modern cryptography technology called elliptic curve cryptography (ECC). The basic expression looks as simple as...

OTP (One Time Password) Card

I had to issue an OTP card so that I can change the maximum amount of bank transfer in the banking app. To strengthen...

RSA – public key cryptosystem

RSA is a very famous public key cryptosystem and I think it’s one of the greatest inventions of software engineering/information technology. It shouldn’t hurt...

GMP for big integer arithmetic

Now I’m back to my cryptography study after a long rest. My next target is RSA algorithm which requires big integer arithmetics. I decided...

FreeStyle Libreをバラしてみました

ピッタリ2週間で使えなくなったされたLibreをバラしてみました。 真ん中の黒いのが腕にささってました。長さ5ミリ。すごくフニャフニャです。専用センサ取り付けツールを使わないと真っ直ぐささりそうもありません。 しっかりくっついているフタをこじあけました。ボタン電池、チップ、温度センサ?外周の丸いパターンはNFCのアンテナのようです。チップは完全カスタムとおもいきやTIの既製品(またはそのカスタマイズ品)のようです。この方も分解されてます。4年前のものですが基盤はまったく同じですね。...

혈당 측정 이야기

제가 그 동안 탄수화물 섭취, 저당질 다이어트에 대해서 배우면서 제 몸의 혈당치가 어떻게 되어 있는지 너무 궁금해서 드디어 연속적 포도당 모니터링 (Continuous Glucose Monitoring:...

Server Name Indication (SNI)

Now that I could link OpenSSL library to my program, I tried to use it for a simple client connection to a TLS server....