paschalis / hardware-login-key

The hardware key provides a simple and secure way to log into systems or websites by automating the login process through a physical button press. The project includes both C and C++ implementations, as well as 3D printed case.

🔐 Hardware Login Key

Introduction

This project offers a straightforward solution for securely logging into a system or website using a hardware key. By pressing a physical button connected to an ATtiny85 microcontroller, users can automate the login process, thereby reducing the risk of password exposure.

🎯 Purpose

The aim of this project is to provide a more secure alternative to manually typing long or complex passwords, particularly in environments where there may be observers or surveillance. With the hardware key, users can log in quickly and securely without the risk of their password being intercepted or observed.

Benefits

• Enhanced Security: Prevents password interception by keystroke loggers or shoulder surfing.
• Convenience: Simplifies the login process, especially for systems with lengthy or complex passwords.
• Privacy: Maintains the confidentiality of passwords in public or shared environments.
• Portability: Easily carried and used on multiple systems or devices.

How it Works

The hardware key utilizes an ATtiny85 microcontroller with the V-USB library to implement USB Human Interface Device (HID) keyboard functionality. This allows the ATtiny85 to act as a keyboard when connected to a computer via USB. When the button connected to the ATtiny85 is pressed, it sends predefined keystrokes to the computer, automating the login process.

📁 Folder Structure

C_implementation

• single_file_project
• multi_file_project

CPP_implementation

• single_file_project
• multi_file_project

3d_printed_case

• hardware_key_case.stl

PCB_Designs

• Through-Hole_DIP
• SMD
• SMD_SOIC
• SMD_QFN

Compilation Instructions

You can modify the permissions of /dev/ttyACM0 to facilitate communication with your serial device. For detailed instructions, click here.

C Implementation

To compile the C implementation, follow these steps:

1. Open a terminal.
2. Navigate to the C_implementation folder.
3. Read the instructions or refer to using make for the C implementation.

C++ Implementation

To compile the C++ implementation, follow these steps:

1. Open a terminal.
2. Navigate to the CPP_implementation folder.
3. Read the instructions for the C++ implementation.

📋 Usage

1. Connect the hardware key to the computer.
2. Press the button on the hardware key.
3. The hardware key sends the predefined keystrokes for logging in.
4. The user is logged in securely without typing the password manually.

PCB Designs

In KiCad

The hardware key is available in multiple PCB package versions to accommodate different assembly preferences:

• Through-Hole (DIP): Easy to assemble manually, suitable for prototyping.
  • With tactile switch.
• SMD (SOIC): For more compact and automated assembly.
  • With tactile switch.
• SMD (QFN): For advanced designs requiring a small footprint.

  • With tactile switch.

  • QFN PCB designed for a touch pad without using the TTP223 IC. (Uses a basic capacitive touch sensing method by measuring changes in capacitance with the microcontroller’s ADC.)

  • QFN PCB designed for a touch pad using the TTP223 IC for enhanced reliability.

    • Uses a simple high/low output for touch detection, similar to a tactile switch, providing a straightforward 0 or 1 output.
    • The PCB is designed with 4 layers to optimize signal integrity and reliability.

In Fusion 360

You can view the design files and images for each PCB version in the PCB_Designs folder.

🛒 Requirements

DIP Version

Reference	Value	Datasheet	Footprint	Qty	DNP
C1, C2	22pF	~	Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P5.00mm	2
C3	0.1uF	~	Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P5.00mm	1
D1	LED GREEN	~	LED_THT:LED_D3.0mm	1
D2	LED RED	~	LED_THT:LED_D3.0mm	1
J1	USB-AM-S-X-X-TH		USB-AM-S-X-X-TH:SAMTEC_USB-AM-S-X-X-TH	1
R1, R3	10k	~	Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal	2
R2	330	~	Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal	1
R4	1k5	~	Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal	1
S1	B3F-1000	~	B3F-1000:SW_B3F-1000	1
U1	ATtiny85-20P	Datasheet	Package_DIP:DIP-8_W7.62mm	1
Y1	12MHz	~	Crystal:Crystal_HC49-4H_Vertical	1

3D model of the hardware login key’s PCB using the Through-Hole (DIP) package in KiCad

3D model of the hardware login key’s PCB using the Through-Hole (DIP) package in Fusion 360

SMD Version (SOIC)

Reference	Value	Datasheet	Footprint	Qty	DNP
C1, C2	22pF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	2
D1	LED RED	~	LED_SMD:LED_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
D2	LED GREEN	~	LED_SMD:LED_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
J1	USB-AM-S-X-X-TH		USB-AM-S-X-X-TH:USB_PCB	1
R1, R3	10k	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	2
R2	330	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
R4	1k5	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
S2	PTS525SM15SMTR2LFS		PTS525SM15SMTR2LFS:SW_PTS525SM15SMTR2LFS	1
U1	ATtiny85-20S	Datasheet	Package_SO:SOIC-8W_5.3x5.3mm_P1.27mm	1
Y1	12MHz	~	Crystal:Crystal_SMD_0603-2Pin_6.0x3.5mm_HandSoldering	1

3D model of the hardware login key’s PCB using the SMD (SOIC) package in KiCad.

SMD Version (QFN)

Reference	Value	Datasheet	Footprint	Qty	DNP
C1, C2	22pF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	2
D1	LED RED	~	LED_SMD:LED_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
D2	LED GREEN	~	LED_SMD:LED_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
J1	USB-AM-S-X-X-TH		USB-AM-S-X-X-TH:USB_PCB	1
R1, R3	10k	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	2
R2	330	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
R4	1k5	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
S2	PTS525SM15SMTR2LFS		PTS525SM15SMTR2LFS:SW_PTS525SM15SMTR2LFS	1
U1	ATtiny85-20M	Datasheet	Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm_ThermalVias	1
Y1	12MHz	~	Crystal:Crystal_SMD_0603-2Pin_6.0x3.5mm_HandSoldering	1

3D model of the hardware login key’s PCB using the QFN package in KiCad.

SMD Version (QFN) with Reversible USB and Touch Functionality

Reference	Value	Datasheet	Footprint	Qty	DNP
C1, C2	22pF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	2
C3	0.1uF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	1
C4	10uF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	1
D1	LED RED	~	Library:LED_Kingbright_APA1606_1.6x0.6mm_Horizontal_NEW	1
D2	LED GREEN	~	Library:LED_Kingbright_APA1606_1.6x0.6mm_Horizontal_NEW	1
J1	USB-AM-S-X-X-TH		USB-AM-S-X-X-TH:USB_PCB	1
R1, R3	10k	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	2
R2	330	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
R4	1k5	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
TP1, TP2	TestPoint	~	TestPoint:TestPoint_Pad_D3.0mm	2
U1	ATtiny85-20M	Datasheet	Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm_ThermalVias	1
Y1	12MHz	~	Crystal:Crystal_SMD_0603-2Pin_6.0x3.5mm_HandSoldering	1

3D model of the hardware login key’s PCB using the QFN package in KiCad.
Without the TTP223 IC. (Uses basic capacitive touch sensing with the microcontroller’s ADC and custom code for detection.)

Reference	Value	Datasheet	Footprint	Qty	DNP
C1,C2	22pF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	2
C3	0.1uF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	1
C4	1uF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	1
C5	30pF	~	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	1
D1	LED RED	~	Library:LED_Kingbright_APA1606_1.6x0.6mm_Horizontal_NEW	1
D2	LED GREEN	~	Library:LED_Kingbright_APA1606_1.6x0.6mm_Horizontal_NEW	1
J1	USB-AM-S-X-X-TH		USB-AM-S-X-X-TH:USB_PCB	1
R1	10k	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
R2	330	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
R4	1k5	~	Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder	1
TP1,TP2	TestPoint	~	TestPoint:TestPoint_Pad_D3.0mm	2
U1	ATtiny85-20M	Datasheet	Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm_ThermalVias	1
U2	TTP223-BA6	Datasheet	TTP223-BA6:SOT23-6	1
Y1	12MHz	~	Crystal:Crystal_SMD_0603-2Pin_6.0x3.5mm_HandSoldering	1

3D model of the hardware login key’s PCB using the QFN package in KiCad.
With the TTP223 IC. (Uses simple high/low output for touch detection, similar to a tactile switch, with default code for straightforward 0 or 1 output.)

Security Considerations

• Ensure the physical security of the hardware key to prevent unauthorized access.
• Keep the key firmware up-to-date to mitigate potential security vulnerabilities.
• Do not use the hardware key on untrusted or compromised systems.
• Use strong encryption and authentication methods in addition to the hardware key for robust security.

🏗️ 3D Printed Case

A 3D printed case is available for the hardware key. To use it, follow these steps:

1. Open the 3d_printed_case folder.
2. Load the hardware_key_case.stl file into your 3D printer software.
3. Print the case using your 3D printer.
4. Once printed, assemble the hardware key inside the case for added protection and aesthetics.

🧑‍💻 Authors

• 

👥 Contributors

📜 License

This project is licensed under the GPLv3 License - see the LICENSE file for details.

• 

Enjoy your secure hardware login key 🔐! Thank you for visiting Hardware-Login-Key! ✨